7,299 research outputs found

    Thermocouple for heating and cooling of memory metal actuators

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    A semiconductor thermocouple unit is provided for heating and cooling memory metal actuators. The semiconductor thermocouple unit is mounted adjacent to a memory metal actuator and has a heat sink attached to it. A flexible thermally conductive element extends between the semiconductor thermocouple and the actuator and serves as a heat transfer medium during heating and cooling operations

    Three ages of Venus

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    A central question for any planet is the age of its surface. Based on comparative planetological arguments, Venus should be as young and active as the Earth (Wood and Francis). The detection of probable impact craters in the Venera radar images provides a tool for estimating the age of the surface of Venus. Assuming somewhat different crater production rates, Bazilevskiy et al. derived an age of 1 + or - 0.5 billion years, and Schaber et al. and Wood and Francis estimated an age of 200 to 400 million years. The known impact craters are not randomly distributed, however, thus some area must be older and others younger than this average age. Ages were derived for major geologic units on Venus using the Soviet catalog of impact craters (Bazilevskiy et al.), and the most accessible geologic unit map (Bazilevskiy). The crater counts are presented for (diameters greater than 20 km), areas, and crater densities for the 7 terrain units and coronae. The procedure for examining the distribution of craters is superior to the purely statistical approaches of Bazilevskiy et al. and Plaut and Arvidson because the bins are larger (average size 16 x 10(6) sq km) and geologically significant. Crater densities define three distinct groups: relatively heavily cratered (Lakshmi, mountain belts), moderately cratered (smooth and rolling plains, ridge belts, and tesserae), and essentially uncratered (coronae and domed uplands). Following Schaber et al., Grieve's terrestrial cratering rate of 5.4 + or - 2.7 craters greater than 20 km/10(9) yrs/10(6) sq km was used to calculate ages for the geologic units on Venus. To improve statistics, the data was aggregated into the three crater density groups, deriving the ages. For convenience, the three similar age groups are given informal time stratigraphic unit names, from youngest to oldest: Ulfrunian, Sednaian, Lakshmian

    Hiding in Plain Sight: Scrubbing Unwanted Information

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    Steganography is a technique used to hide encrypted messages within multimedia files. This technique was recently reported to have been used by Osama Bin Laden to communicate with terrorist cells within the United States, and, thus, prevention of the transmission of steganographic content is of great interest to those interested in information security. Methods of steganalysis have been developed that attempt to detect files that contain steganographic content. However, authors of these methods admit that they are not viable for production or have been shown to be defeated by newer advances in steganography. This design science research illustrates an innovation in which algorithms neutralize any hidden messages without significantly detracting from the underlying integrity of the multimedia files and without the need for prior detection of steganographic content

    The Doctor\u27s Dilemma: Sin, Salvation, and the Menstrual Cycle in Medieval Thought

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    Because menstruation is a normal process in women of the child-bearing years, historians long tended to overlook its potential interest. An- thropologists might ponder such matters as the rites and taboos with which it was often invested, but theirs was a less prudish field, one that also saw itself as being mainly devoted to the study of unchanging features in traditional cultures. Until recently, on the other hand, historians conceived of their discipline as being primarily concerned with the very procers of change; and since, like the poor, taxes, and death, menstruation has always been with us, it seemed a subject scarcely in need of historical explanation

    Start-up Library: A Report from the Aloha Community Library

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    “Do you have any idea of what is going on in Aloha? ” is how Oregon State Librarian MaryKay Dahlgreen began her speech at the Grand Opening of the Aloha Community Library on September 22, 2012 (Squires, Oct. 4, 2012). The people of Aloha, Oregon have united in an incredibly determined effort to create a library that will serve as a learnin

    Alien Registration- Wood, Charles (Lewiston, Androscoggin County)

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    https://digitalmaine.com/alien_docs/26781/thumbnail.jp

    Jim Crow in New York

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    More than 108,000 New Yorkers cannot vote because of a conviction in their past. Almost half of these disenfranchised citizens have completed their prison sentence and are living and working in the community

    The Eleusinian Mysteries.

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