In-situ Undisturbed Sand Sampling by Radial Freezing for Liquefaction Analysis

The authors experimented in laboratory that if radial freezing with free drainage is performed under an effective confining pressure of 100 kPa only an increase of the order of 0.5% of volumetric strain takes place going from the unfrozen to the frozen condition. The sample comes back to the original dimension after thawing. The displacements of the sample were measured by radiographs of a lead shot network properly built inside the sample. The technique suggested by Yoshimi and al. (1977) to freeze in situ a column of saturated sands was also verified and optimized in laboratory by simulating in a full scale test the site conditions. Finally 3.10 m length and 55 cm. diameter sample of saturated sand was frozen at a well studied site by radial freezing technique, then pulled out from the ground by a crane, sawed and stored in a freezer for future laboratory tests

Racial Reorganization and the United States Census 1850–1930: Mulattoes, Half-Breeds, Mixed Parentage, Hindoos, and the Mexican Race

Between 1850 and 1930, demographic upheaval in the United States was connected to reorganization of the racial order. Socially and politically recognized boundaries between groups shifted, new groups emerged, others disappeared, and notions of who belonged in which category changed. All recognized racial groups—blacks, whites, Indians, Asians, Mexicans and others—were affected. This article investigates how and why census racial classification policies changed during this period, only to stabilize abruptly before World War II. In the context of demographic transformations and their political consequences, we find that census policy in any given year was driven by a combination of scientific, political, and ideological motivations. Based on this analysis, we rethink existing theoretical approaches to censuses and racial classification, arguing that a nation’s census is deeply implicated in and helps to construct its social and political order. Censuses provide the concepts, taxonomy, and substantive information by which a nation understands its component parts as well as the contours of the whole; censuses both create the image and provide the mirror of that image for a nation’s self-reflection. We conclude by outlining the meaning of this period in American history for current and future debates over race and classification.Governmen

Beaked whales respond to simulated and actual navy sonar

This article is distributed under the terms of the Creative Commons Public Domain declaration. The definitive version was published in PLoS One 6 (2011): e17009, doi:10.1371/journal.pone.0017009.Beaked whales have mass stranded during some naval sonar exercises, but the cause is unknown. They are difficult to sight but can reliably be detected by listening for echolocation clicks produced during deep foraging dives. Listening for these clicks, we documented Blainville's beaked whales, Mesoplodon densirostris, in a naval underwater range where sonars are in regular use near Andros Island, Bahamas. An array of bottom-mounted hydrophones can detect beaked whales when they click anywhere within the range. We used two complementary methods to investigate behavioral responses of beaked whales to sonar: an opportunistic approach that monitored whale responses to multi-day naval exercises involving tactical mid-frequency sonars, and an experimental approach using playbacks of simulated sonar and control sounds to whales tagged with a device that records sound, movement, and orientation. Here we show that in both exposure conditions beaked whales stopped echolocating during deep foraging dives and moved away. During actual sonar exercises, beaked whales were primarily detected near the periphery of the range, on average 16 km away from the sonar transmissions. Once the exercise stopped, beaked whales gradually filled in the center of the range over 2–3 days. A satellite tagged whale moved outside the range during an exercise, returning over 2–3 days post-exercise. The experimental approach used tags to measure acoustic exposure and behavioral reactions of beaked whales to one controlled exposure each of simulated military sonar, killer whale calls, and band-limited noise. The beaked whales reacted to these three sound playbacks at sound pressure levels below 142 dB re 1 µPa by stopping echolocation followed by unusually long and slow ascents from their foraging dives. The combined results indicate similar disruption of foraging behavior and avoidance by beaked whales in the two different contexts, at exposures well below those used by regulators to define disturbance.The research reported here was financially supported by the United States (U.S.) Office of Naval Research (www.onr.navy.mil) Grants N00014-07-10988, N00014-07-11023, N00014-08-10990; the U.S. Strategic Environmental Research and Development Program (www.serdp.org) Grant SI-1539, the Environmental Readiness Division of the U.S. Navy (http://www.navy.mil/local/n45/), the U.S. Chief of Naval Operations Submarine Warfare Division (Undersea Surveillance), the U.S. National Oceanic and Atmospheric Administration (National Marine Fisheries Service, Office of Science and Technology) (http://www.st.nmfs.noaa.gov/), U.S. National Oceanic and Atmospheric Administration Ocean Acoustics Program (http://www.nmfs.noaa.gov/pr/acoustics/), and the Joint Industry Program on Sound and Marine Life of the International Association of Oil and Gas Producers (www.soundandmarinelife.org)

Live-Out Register Fencing

This article introduces Live-Out Register Fencing (LoRF), a soft error correction mechanism that uses the novel Spill Register File as a container of checkpointing data. LoRF’s Spill Register File holds the values shared among basic blocks in the program, and, coupled with a new compilation strategy, LoRF allows for error correction in the same basic block where the error was detected. In LoRF, error correction is triggered by a hardware interrupt that restores the registers of a basic block from the Spill Register File. After these registers are restored, the basic block where the error was detected can just be re-executed, thus reducing the costs of error recovery. LoRF’s error correction policy eliminates the need for expensive architectural support for checkpointing and rollback, reducing the performance overhead of online soft error correction. LoRF relies on both a modified processor architecture and a corresponding compiler. The architecture was implemented in synthesizable VHDL, whereas the compiler was developed as an extension of the LLVM framework. Fault injection experiments support an error correction coverage of 99.35% and a mean performance overhead of 1.33 for the entire life cycle of an error from its occurrence to its elimination from the system. </jats:p