10,117 research outputs found

    Flush mounting of thin film sensors

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    Flush mounting of a sensor on a surface is provided by first forming a recessed area on the surface. Next, an adhesive bonding mixture is introduced into the recessed area. The adhesive bonding mixture is chosen to provide thermal expansion matching with the surface surrounding the recessed area. A strip of high performance polymeric tape is provided, with the sensor attached to the underside thereof, and the tape is positioned over the recessed area so that it acts as a carrier of the sensor. A shim having flexibility so that it will conform to the surface surrounding the recessed area is placed over the tape, and a vacuum pad is placed over the shim. The area above the surface is then evacuated while holding the sensor flush with the surface during curing of the adhesive bonding mixture. After such curing, the pad, shim, and tape are removed from the sensor, electrical connections for the sensor are provided, after which the remaining space in the recessed area is filled with a polymeric foam

    Practical approaches for application of resistance type strain gages on high temperature composites

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    Four major areas of interest with respect to utilizing strain gages on carbon/carbon (with SiC surfaces) and titanium matrix composites are addressed. Strain gage and adhesive combinations on carbon/carbon (C/C) at temperatures from minus 190 C to to 540 C, half-bridge gaging for reducing apparent strain on C/C using Poisson's ratio and bending configurations, a review of the 'field installation' techniques developed for gaging a C/C hypersonic generic elevon, and results of initial strain gaging efforts on titanium matrix composites are discussed. Current research in developing techniques for increasing the maximum temperature for strain gages on carbon/carbon are reviewed

    The 22-Year Hale Cycle in Cosmic Ray Flux – Evidence for Direct Heliospheric Modulation

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    Abstract The ability to predict times of greater galactic cosmic ray (GCR) fluxes is important for reducing the hazards caused by these particles to satellite communications, aviation, or astronauts. The 11-year solar-cycle variation in cosmic rays is highly correlated with the strength of the heliospheric magnetic field. Differences in GCR flux during alternate solar cycles yield a 22-year cycle, known as the Hale Cycle, which is thought to be due to different particle drift patterns when the northern solar pole has predominantly positive (denoted as qA>0 cycle) or negative (qA0 cycles than for qA0 and more sharply peaked for qA0 solar cycles, when the difference in GCR flux is most apparent. This suggests that particle drifts may not be the sole mechanism responsible for the Hale Cycle in GCR flux at Earth. However, we also demonstrate that these polarity-dependent heliospheric differences are evident during the space-age but are much less clear in earlier data: using geomagnetic reconstructions, we show that for the period of 1905 – 1965, alternate polarities do not give as significant a difference during the declining phase of the solar cycle. Thus we suggest that the 22-year cycle in cosmic-ray flux is at least partly the result of direct modulation by the heliospheric magnetic field and that this effect may be primarily limited to the grand solar maximum of the space-age

    Detecting malware in memory with memory object relationships

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    Malware is a growing concern that not only affects large businesses but the basic consumer as well. As a result, there is a need to develop tools that can identify the malicious activities of malware authors. A useful technique to achieve this is memory forensics. Memory forensics is the study of volatile data and its structures in Random Access Memory (RAM). It can be utilized to pinpoint what actions have occurred on a computer system. This dissertation utilizes memory forensics to extract relationships between objects and supervised machine learning as a novel method for identifying malicious processes in a system memory dump. In this work, the Object Association Extractor (OAE) was created to extract objects in a memory dump and label the relationships as a graph of nodes and edges. With OAE, we extracted processes from 13,882 memory images that contained malware from the repository VirusShare and 91 memory images created with benign software from the package management software Chocolatey. The final dataset contained 267,824 processes. Two feature sets were created from the processes dataset and used to train classifiers based on four classification algorithms. These classifiers were evaluated against the ZeroR method using accuracy and recall as the evaluation metrics. The experiments showed that both sets of features used to build classifiers were able to beat the ZeroR method for the Decision Tree and Random Forest algorithms. The Random Forest classifier achieved the highest performance by reaching a recall score of almost 97%

    A Recommended Program Of Principal-Teacher Supervision For Center Point School, Pittsburg, Texas

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    Background and development of Modern Supervision Not with standing the fact we have a different type of supervision today than was practiced when public schools in America were first established, supervision has existed ever since the formation of the first public school system. When the General Court of Boston, directed by the selectmen, was instructed to secure teachers with certain religious training, a type of supervision was being carried on. That custom was followed for nearly fifty years, at which time the teachers came under more formal supervision. The schools, using Boston as an illustration, were supervised by a committee, who was appointed to visit the school, Inspect the plant and equipment and examine the achievement of the pupils, These supervisors did not criticize the teachers, neither did they advise them. It Is noticeable that by 1714 supervision in the United States had passed through three phases. During the first phase, the supervisors selected the teachers. During the second phase, the supervisors selected the teachers and inspected the plant and the equipment. During the third phase, they had the added responsibility of criticizing and advising the teachers. By 1721 supervision was done by the selectmen and any others that they decided to invite

    James G. Thomas, Sr.

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    https://egrove.olemiss.edu/lebanese_interviews/1012/thumbnail.jp

    Recommended Strain Gage Application Procedures for Various Langley Research Center Balances and Test Articles

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    The NASA Langley Research Center uses more than 10000 strain gages per year in supporting its various research programs. The character of the testing at LaRC is such that the types of strain gage installations, the materials they are applied to, and the test environments encountered, require many varied approaches for installing strain gages. These installations must be accomplished in the most technically discerning and appropriate manner. This technical memorandum is offered as an assisting guide in helping the strain gage user to determine the appropriate approach for a given strain gage application requirement. Specifically, this document offers detailed recommendations for strain gaging the following: LaRC-Designed balances, LARC custom transducers, certain composite materials and alloys, high-temperature test articles, and selected non-typical or unique materials or test conditions
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