English literature | EPFL Graph Search

English literature is literature written in the English language from the United Kingdom, its Crown Dependencies and Overseas Territories, the Republic of Ireland, the United States, and the countries of the former British Empire. The English language has developed over the course of more than 1,400 years. The earliest forms of English, a set of Anglo-Frisian dialects brought to Great Britain by Anglo-Saxon invaders in the fifth century, are called Old English. Beowulf is the most famous work in Old English, and has achieved national epic status in England, despite being set in Scandinavia. However, following the Norman conquest of England in 1066, the written form of the Anglo-Saxon language became less common. Under the influence of the new aristocracy, French became the standard language of courts, parliament, and polite society. The English spoken after the Normans came is known as Middle English. This form of English lasted until the 1470s, when the Chancery Standard (late Middle

Resynchronization of islanded unbalanced ADNs: Control, synchrocheck and experimental validation

Sherif Alaa Salaheldin Fahmy, Mario Paolone, Quentin Walger

The problem of securely reconnecting active distribution networks (ADNs) - e.g. microgrids - to their upstream grids at the point of common coupling (PCC) has been extensively discussed by the existing literature. The latter is commonly referred to as resynchronization and has to be done with care in order to avoid large transient current flows resulting from differences of nodal voltage phasors at both sides of the PCC. The active resynchronization process can be split into two tasks: the PCC-control and the synchrocheck. The PCC-control refers to the process used to steer the PCC nodal voltage at the ADN's side (i.e. downstream) towards the PCC nodal voltage at the upstream-grid's side (i.e. upstream). The synchrocheck refers to the algorithm used to check the synchronization (i.e. phasor alignment within tolerances) of the upstream and downstream PCC nodal voltages. Methods for PCC-control and synchrocheck presented in the literature commonly ignore the ADN's operational constraints and rely on the assumption of a balanced system. In this respect, the contribution of this paper is twofold. First, an approximated optimal-power-flow is proposed to control ADNs' resources in order to rapidly steer their PCC downstream nodal voltages close to their non-controllable upstream counterparts. Second, an Interpolated-Discrete-Fourier-Transform (IpDFT)-based synchrocheck that verifies the alignment of all three-phases of both upstream and downstream nodal voltages at the PCC, is proposed. The algorithms associated to both contributions are experimentally validated on the CIGRE-low-voltage-benchmark-microgrid at the Distributed Electrical Systems Laboratory (DESL) at the ecole Polytechnique Federale de Lausanne (EPFL) where the results of the developed synchrocheck are further benchmarked against the Schneider Electric's Micom P143 grid relay.

ELSEVIER SCIENCE SA2022

Pollution transport efficiency toward the Arctic: Sensitivity to aerosol scavenging and source regions

Isabelle Bey, Quentin Bourgeois

The processes driving current changes in Arctic atmospheric composition and climate are still uncertain. In particular the relative contributions of major source regions from the midlatitudes remain a matter of debate in the literature. The objectives of this study are to better quantify the relative contributions of different processes governing the transport of pollution from the midlatitudes to the Arctic and the relative contributions of different geopolitical source regions. We use a suite of observational data sets (including the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaigns and the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) satellite instrument) to constrain a global aerosol simulation from the ECHAM5-HAMMOZ model. Preliminary comparison of model results with vertical profiles of sulfate and black carbon (BC) collected during the ARCTAS campaigns and with aerosol extinction time series retrieved from CALIOP indicates that the model underestimates export of aerosols from the planetary boundary layer to the free troposphere in the midlatitudes and long-range transport of aerosols from the midlatitudes toward the Arctic. In contrast, observed CO profiles are relatively well simulated, which points to a possible problem with wet scavenging. Decreasing the prescribed aerosol scavenging coefficients within the range of experimental data available in the literature significantly improves the agreement with observations. Sulfate and BC burdens in the Arctic increase by a factor 5-6. Annual global lifetimes of sulfate and BC increase from 3.1 to 4.6 days and from 4.4 to 5.9 days, respectively. Using the improved simulation, we find that 59% of sulfate in the Arctic troposphere comes from the oxidation of SO2 emitted in Siberia (19%), Europe (18%), Asia (13%), and North America (9%). Anthropogenic and biomass burning BC emitted in Siberia, Asia, Europe, and North America contributes 29, 27, 25, and 17%, respectively, to the Arctic BC burden. Emissions of aerosols (or precursors) from Siberia and Europe are more susceptible to be transported and subsequently deposited on the Arctic (about 7-12%) compared to those from North America and Asia (1-4%). Overall, the study shows that aerosol scavenging removal processes play a crucial role on the aerosol transport from the midlatitudes toward the Arctic and should be carefully characterized in aerosol models.

2011

The role of demand in fostering product vs process innovation: a model and an empirical test

Gabriele Pellegrino

While the extant innovation literature has provided extensive evidence of the so-called "demand-pull" effect, the possible diverse impact of demand evolution on product vs process innovation activities has not been yet investigated. This paper develops a formal model predicting a larger inducing impact of past sales in fostering product rather than process innovation. This prediction is then tested through a dynamic microeconometric model, controlling for R&D persistence, sample selection, observed and unobservable individual firm effects and time and sectoral peculiarities. Results are consistent with the model and suggest that an expansionary economic policy may benefit the diffusion of new products or even the emergence of entire new sectors.