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利用新的木材防腐剂处理木材坚固件的腐蚀
This document compiles recent research findings related to corrosion of metals in preservative treated wood into a single report on corrosion of metals in wood. The research was conducted as part of the Research, Technology and Education portion of the National Historic Covered Bridge Preservation (NHCBP) Program administered by the Federal Highway Administration. The compilation addresses: corrosion rates of metals embedded in treated wood, the mechanism of corrosion in treated wood, the effect of extractives on corrosion, methods for predicting the service life of metals in treated wood, and suitable non-metallic replacement fasteners. The document was created to serve as a desk reference for engineers to aid in materials selection when building with treated wood.
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新型功能高分子聚合物增强C-IED运营中变化检测
A novel fluorophore tagged exopolysaccharide (TEPS) was developed, synthesized, and tested for its potential implications toward locating Improvised Explosive Device (IEDs). Our TEPS exhibited unique and substantial properties that lend well to current change detection processing techniques and allows for significantly improved detection of objects implanted into the natural landscape. When coupled with a novel image processing package, or Automated Disturbance Detection System (ADDS), that automatically processes images, and creates a map of areas of interest (AOIs) that relate to the detection of a hidden object, TEPS has shown great success. For example, in pilot scale field testing it was able to accurately and automatically identify large (larger than 12') implanted devices nearly 100of the time and smaller objects (between 1' and 12') 87.5of the time from an aerial platform. Furthermore, the system only falsely detected one terrestrial disturbance for every fourteen that it correctly identified. An additional benefit of our TEPS system is that its computational requirements will be about 75less than comparable systems because computationally intense preprocessing algorithms are unnecessary. The combined TEPS and ADDS technologies can rapidly produce maps of AOIs, which would ultimately allow for greater and safer movement of troops in dangerous areas.
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测定玻璃和玻璃态聚合物独特的断裂模式
The study of fractures of glass, glassy type materials, and plastic has long been of interest to the forensic community. The focus of this interest has been the use of glass and polymer fractures to reconstruct past events and to associate items of evidence. One example of this association is the matching of glass fragments from various locations where they can be shown to have come from a common origin. In the materials science community, fractography is the means and methods for characterization of fractured specimens or components in order to study or identify the mechanism of such failures, which is the focus on most of the literature on the subject. The ability to show that each and every fracture is, in fact, unique has not been a matter of consequence or of interest to the engineering or scientific community. In contrast, the basic premise that fractures are not likely to be reproducible is very relevant to the forensic science community. The issue arises when a given fracture pattern is restored or component pieces are physically fitted together and 'matched' and the conclusion is drawn that this is unlikely to be possible unless all the components were derived from the same part. Despite the importance of this assumption, very limited research has actually been done to confirm that this is indeed the case. This study documented the very controlled fracture patterns of 60 glass panes, 60 glass bottles, and 60 plastic tail light lens covers. The pane and bottle specimens were fractured with three different types of penetration tips: sharp tip, round tip, and blunt tip.