A flight investigation of simulated data-link communications during single-pilot IFR flight. Volume 2: Flight evaluations

Key problems in single pilot instrument flight operations are in the management of flight data and the processing of cockpit information during conditions of heavy workload. A flight data console was developed to allow simulation of a digital data link to replace the current voice communications stem used in air traffic control. This is a human factors evaluation of a data link communications system to determine how such a system might reduce cockpit workload, improve flight proficiency, and be accepted by general aviation pilots. The need for a voice channel as backup to a digital link is examined. The evaluations cover both airport terminal area operations and full mission instrument flight. Results show that general aviation pilots operate well with a digital data link communications system. The findings indicate that a data link system for pilot/ATC communications, with a backup voice channel, is well accepted by general aviation pilots and is considered to be safer, more efficient, and result in less workload than the current voice system

A flight investigation of simulated data link communications during single-pilot IFR flight

A Flight Data Console (FDC) was developed to allow simulation of a digital communications link to replace the current voice communication system used in air traffic control (ATC). The voice system requires manipulation of radio equipment, read-back of clearances, and mental storage of critical information items, all contributing to high workload, particularly during single-pilot operations. This was an inflight study to determine how a digital communications system might reduce cockpit workload, improve flight proficiency, and be accepted by general aviation pilots. Results show that instrument flight, including approach and landing, can be accomplished quite effectively using a digital data link system for ATC communications. All pilots expressed a need for a back-up voice channel. When included, this channel was used sparingly and principally to confirm any item of information about which there might be uncertainty

A flight investigation of simulated data-link communications during single-pilot IFR flight. Volume 1: Experimental design and initial test

A Flight Data Console simulation of a digital communication link to replace the current voice communication system used in air traffic control (ATC) was developed. The study determined how a digital communications system reduces cockpit workload, improve, flight proficiency, and is acceptable to general aviation pilots. It is shown that instrument flight, including approach and landing, can be accomplished by using a digital data link system for ATC communication

Contact line motion for partially wetting fluids

We study the flow close to an advancing contact line in the limit of small capillary number. To take into account wetting effects, both long and short-ranged contributions to the disjoining pressure are taken into account. In front of the contact line, there is a microscopic film corresponding to a minimum of the interaction potential. We compute the parameters of the contact line solution relevant to the matching to a macroscopic problem, for example a spreading droplet. The result closely resembles previous results obtained with a slip model

Dynamic RKKY interaction between magnetic moments in graphene nanoribbons

Graphene has been identified as a promising material with numerous applications, particularly in spintronics. In this paper we investigate the peculiar features of spin excitations of magnetic units deposited on graphene nanoribbons and how they can couple through a dynamical interaction mediated by spin currents. We examine in detail the spin lifetimes and identify a pattern caused by vanishing density of states sites in pristine ribbons with armchair borders. Impurities located on these sites become practically invisible to the interaction, but can be made accessible by a gate voltage or doping. We also demonstrate that the coupling between impurities can be turned on or off using this characteristic, which may be used to control the transfer of information in transistor-like devices.Comment: 10 pages, 10 figure

A design research approach

The significance of the design process in determining the success or failure of a product in the market place is becoming increasingly more articulated. Consequently companies are implementing and developing new techniques and tools to support design more effectively. Design research is directed at gaining a greater understanding of design, ultimately to better support it through the development of improved techniques, methods or tools

Application of remote sensing to state and regional problems

The methods and procedures used, accomplishments, current status, and future plans are discussed for each of the following applications of LANDSAT in Mississippi: (1) land use planning in Lowndes County; (2) strip mine inventory and reclamation; (3) white-tailed deer habitat evaluation; (4) remote sensing data analysis support systems; (5) discrimination of unique forest habitats in potential lignite areas; (6) changes in gravel operations; and (7) determining freshwater wetlands for inventory and monitoring. The documentation of all existing software and the integration of the image analysis and data base software into a single package are now considered very high priority items

Foundation species identity and trophic complexity affect experimental seagrass communities

The abundance and species composition of marine foundation species is changing due to range expansion or contraction, with potentially important ecosystem-level consequences. In Chesapeake Bay, USA, warming is likely to favor the more heat and stress-tolerant Ruppia maritima (widgeongrass) over Zostera marina (eelgrass). Because of the key role of seagrasses in providing habitat and trophic support, it is important to determine whether the more stress-tolerant seagrass provides similar ecological functions to the species it may replace. We addressed how trophic control differs between communities associated with the 2 seagrass species in a mesocosm experiment. Grazing of epiphytic algae can benefit seagrasses over competing algae, and crustacean mesograzers are an important link for higher trophic levels. We manipulated seagrass density, species identity, and presence of grazers and predators, and examined the resulting communities of recruiting algae and invertebrates. Overall, predation was higher in Ruppia than in Zostera, although mesograzer species individually differed in their susceptibility to predation and response to seagrass species. The presence of grazers and predators had a greater overall effect on multivariate metrics of fouling community development than did seagrass species identity. Initial densities of seagrass and grazer species had interactive effects on some recruiting microalgae and tunicates. Differences in grazer composition and predation between seagrass species could have consequences for higher trophic levels that rely on fauna in seagrass beds. However, given the considerable effects of manipulated seagrass and mesograzer density on trophic interactions and the fouling community, it may be most important to consider the overall density and distribution of seagrass present, rather than seagrass species identity. Our results highlight the importance of testing redundancy in ecological functions among habitat-forming species

C-H...O and C-H...π(arene) interactions in (2S,4S,5R)-(-)-2-(4-propoxyphenyl)-3,4-dimethyl-5-phenyl-1,3-oxazolidine

The title compound, C₂₀H₂₅NO₂, a condensation product of l-ephedrine and 4-propoxyaldehyde, is of interest in studies on weak interactions. It crystallizes with C-H...O and C-H...π(arene) intermolecular interactions as a one-dimensional chain [C...O = 3.3745 (19) Å, C-H...O = 139°; C-H...Cg1 = 3.6987 (16) Å, C-H...Cg1 = 161°, where Cg1 is the centroid of the symmetry-related 4-propoxy-substituted aromatic ring]