Real-time observation of epitaxial graphene domain reorientation.

Graphene films grown by vapour deposition tend to be polycrystalline due to the nucleation and growth of islands with different in-plane orientations. Here, using low-energy electron microscopy, we find that micron-sized graphene islands on Ir(111) rotate to a preferred orientation during thermal annealing. We observe three alignment mechanisms: the simultaneous growth of aligned domains and dissolution of rotated domains, that is, 'ripening'; domain boundary motion within islands; and continuous lattice rotation of entire domains. By measuring the relative growth velocity of domains during ripening, we estimate that the driving force for alignment is on the order of 0.1 meV per C atom and increases with rotation angle. A simple model of the orientation-dependent energy associated with the moiré corrugation of the graphene sheet due to local variations in the graphene-substrate interaction reproduces the results. This work suggests new strategies for improving the van der Waals epitaxy of 2D materials

Nanoscale periodicity in stripe-forming systems at high temperature: Au/W(110)

We observe using low-energy electron microscopy the self-assembly of monolayer-thick stripes of Au on W(110) near the transition temperature between stripes and the non-patterned (homogeneous) phase. We demonstrate that the amplitude of this Au stripe phase decreases with increasing temperature and vanishes at the order-disorder transition (ODT). The wavelength varies much more slowly with temperature and coverage than theories of stress-domain patterns with sharp phase boundaries would predict, and maintains a finite value of about 100 nm at the ODT. We argue that such nanometer-scale stripes should often appear near the ODT.Comment: 5 page

Swine Diets Utilizing Wheat

Previous trials have suggested that, when diets were supplemented at the same level and either corn or wheat was used in the same amount as the grain, pig gains were similar. However, pigs fed corn diets were more efficient in terms of both feed use and cost per pound of grain. Wheat diets supplemented at lower levels or assess the value of wheat\u27s higher protein level relative to corn and fed with or without supplemental lysine did not support satisfactory pig performance in terms of gain, feed efficiency or feed cost. Results of these trials suggested that an intermediate level of protein supplementation for wheat should be investigated. The trial reported here was designed with that objective

Wheat in Swine Finishing Rations

The objectives of the trial reported here were: 1. To compare the performance of pigs fed rations with the same proportions of grain and supplement but with the grain corn in one rations and wheat in another ration. 2. To assess the possible feeding value of wheat\u27s greater protein content by use of an all wheat ration in which there was a lower level of supplemental protein. 3. To assess the value of lysine in wheat rations by the effition of lysine to the same ration as used for comparison 2 (above)

Design, ancillary testing, analysis and fabrication data for the advanced composite stabilizer for Boeing 737 aircraft. Volume 1: Technical summary

The horizontal stabilizer of the 737 transport was redesigned. Five shipsets were fabricated using composite materials. Weight reduction greater than the 20% goal was achieved. Parts and assemblies were readily produced on production-type tooling. Quality assurance methods were demonstrated. Repair methods were developed and demonstrated. Strength and stiffness analytical methods were substantiated by comparison with test results. Cost data was accumulated in a semiproduction environment. FAA certification was obtained

Full-scale testing, production and cost analysis data for the advanced composite stabilizer for Boeing 737 aircraft, volume 2

The development, testing, production activities, and associated costs that were required to produce five-and-one-half advanced-composite stabilizer shipsets for Boeing 737 aircraft are defined and discussed

Design, ancillary testing, analysis and fabrication data for the advanced composite stabilizer for Boeing 737 aircraft, volume 2

Results of tests conducted to demonstrate that composite structures save weight, possess long term durability, and can be fabricated at costs competitive with conventional metal structures are presented with focus on the use of graphite-epoxy in the design of a stabilizer for the Boeing 737 aircraft. Component definition, materials evaluation, material design properties, and structural elements tests are discussed. Fabrication development, as well as structural repair and inspection are also examined

Habitat assessment and ecological restoration design for an unnamed tributary of Stone Dam Creek, Conway, Arkansas

Urbanization can lead to increased sedimentation, erosion, pollution, and runoff into streams. The United States Environmental Protection Agency’s (USEPA) Rapid Bioassessment Protocols (RBPs) are sets of guidelines that can be used to assess a habitat’s sedimentology, hydrology, vegetation, and geomorphology to determine impairment. An unnamed tributary of Stone Dam Creek on the University of Central Arkansas (UCA) campus in Conway, Arkansas runs partially underground and through the urbanized UCA campus watershed. The stream was assessed using the USEPA’s RBPs to determine impairment of the stream, and received a RBP score of 71.2 out of 200 compared to 153.5 in a reference stream. An ecological restoration design was then prepared for a 2-year, 1-hour rainfall event to address areas of impairment. The goal was to increase the RBP score by increasing cross-sectional area of the stream as well as by improving stream morphology where possible. With the proposed design, modeled stream velocity was reduced throughout the stream by an average of 19.6%. It was assessed that as a result of the reduction in velocity and changes to morphology, RPB scores would increase throughout the stream reach