Sputtering Holes with Ion Beamlets

Ion beamlets of predetermined configurations are formed by shaped apertures in the screen grid of an ion thruster having a double grid accelerator system. A plate is placed downstream from the screen grid holes and attached to the accelerator grid. When the ion thruster is operated holes having the configuration of the beamlets formed by the screen grid are sputtered through the plate at the accelerator grid

Sulfur oxidizing capacity of California desert soils

Sulfur oxidation in desert soils due to bacterial activit

Preliminary design of graphite composite wing panels for commercial transport aircraft

Subjectively assessed practical and producible graphite/epoxy designs were subjected to a multilevel screening procedure which considered structural functions, efficiency, manufacturing and producibility, costs, maintainability, and inspectability. As each progressive screening level was reviewed, more definitive information on the structural efficiency (weight), manufacturing, and inspection procedures was established to support the design selection. The configuration features that enhance producibility of the final selected design can be used as a generic base for application to other wing panel designs. The selected panel design showed a weight saving of 25 percent over a conventional aluminum design meeting the same design requirements. The estimated cost reduction in manufacturing was 20 percent, based on 200 aircraft and projected 1985 automated composites manufacturing capability. The panel design background information developed will be used in the follow-on tasks to ensure that future panel development represents practical and producible design approaches to graphite/epoxy wing surface panels

Systematic description and key to isolants from Atacama Desert, Chile

Isolation and identification of desert soil microorganism from Chil

Factors influencing the language use of preschool children in a child/parent education program

This study examines factors that influence the language use of preschool children in a child/parent education program. The Preschool for Child/Parent Education Project was initiated to address concerns for at risk children and their families in the community of Nipawin, Saskatchewan. The families invited to participate in the program were identified as having preschool children who were potentially at risk for school success. The language experiences of four preschool children were observed as they participated in one nine-week child/parent education session. The parents, caregivers and preschool teacher were interviewed regarding their views about the language experiences of the children. The factors that emerged as having an influence on the children's use of language in the preschool program were: play center activities, direct instruction, authentic experiences, parent/caregiver involvement and teacher efficacy. Results showed that the children in the Preschool for Child/Parent Education Project experienced a program that understood the language needs of young children and the powerful influence of a supportive family. Implications are drawn concerning the benefits of providing opportunities for language development and use during the crucial preschool years in a child/parent education program. Recommendations for further research suggest recognition of the effects of early language intervention on young children with difficult life circumstances

INVESTIGATING THE SPATIAL BEHAVIOR AND HABITAT USE OF THE MATSCHIE’S TREE-KANGAROO (DENDROLAGUS MATSCHIEI) USING GPS COLLARS AND UNMANNED AIRCRAFT SYSTEMS (UAS)

Understanding the movement patterns and habitat needs of the endangered Matschie’s tree-kangaroo (Dendrolagus matschiei) is important for their conservation and management. Endemic to the montane cloud forests of the Huon Peninsula in northeastern Papua New Guinea, these elusive arboreal marsupials are tremendously challenging to study using traditional observational methods. This study is an assessment of novel techniques to overcome the significant challenges to in-situ data collection in remote and rugged tropical cloud forests. Animal locations are remotely tracked using purpose built altitude and motion logging GPS collars and habitat structure data is measured using photogrammetry from small Unmanned Aircraft Systems (UAS) aerial imagery. Leveraging the autocorrelation of regular GPS location sampling, this study applied a Time-Local Convex Hull (T-LoCoH) analysis to investigate particular locations that may be important to D. matschiei as well as potential barriers to movement that would be inside of the home range as identified in previous studies. A novel technique of ground surface interpolation from canopy gaps is presented to overcome the challenges of photogrammetric reconstruction of terrain surfaces under closed canopy forests. From this a variety of forest structure variables were calculated to understand the 3D complexity of these heterogeneous cloud forests. This investigation found that custom GPS collars can provide high fix success rates in dense multilayer forests found at the research site. The regular sampling intervals resulted in areas of utilization that were notably smaller than with traditional home range analyses, and provided insight into landscape features that the animals do not use. D. matschiei were found to preferentially use trees that were taller than average and were found in closer than average proximity to canopy emergent trees. The reconstruction of 3D habitat data from UAS aerial photogrammetry resulted in forest structure maps that have significant potential to overcome the necessity of manual habitat data collection that hinders large scale habitat research, for this and many other species

Singing Bird : Indian Intermezzo

https://digitalcommons.library.umaine.edu/mmb-ps/1657/thumbnail.jp

Behavior of damaged graphite/epoxy laminates under compression loading

The influence of three different resin systems on the damage tolerance of graphite/polymer laminates was evaluated. Testing consisted of both static compression and cyclic compression evaluation of 10.2 by 15.2 by 0.5 cm (4 by 6 by 0.2 in) laminates with circular holes, simulated delaminations, and low velocity impact. Damage growth under steadily increasing compression and cyclic compression loading was monitored. Damage size and impact-induced failures for the three materials were compared. Of the three material systems evaluated, the one most tolerant to impact damage exhibited the least delamination within the cross section due to impact, the highest transverse tension strain to failure, and the largest crack opening force, as determined from double cantilever beam tests