Extended performance solar electric propulsion thrust system study. Volume 1: Executive summary

Several thrust system design concepts were evaluated and compared using the specifications of the most advanced 30 cm engineering model thruster as the technology base. The extensions in thruster performance required for the Halley's comet mission were defined and alternative thrust system concepts were designed. Confirmation testing and analysis of thruster and power-processing components were performed, and the feasibility of satisfying extended performance requirements was verified. A baseline design was selected from the alternatives considered, and the design analysis and documentation were refined. A program development plan was formulated that outlines the work structure considered necessary for developing, qualifying, and fabricating the flight hardware for the baseline thrust system within the time frame of a project to rendezvous with Halley's comet. An assessment was made of the costs and risks associated with a baseline thrust system as provided to the mission project under this plan. Critical procurements and interfaces were identified and defined. Results are presented

A Plan of Farm Organization for Hill Land Farms in Southeastern Ohio

Exact date of bulletin unknown.PDF pages: 2

Extended performance solar electric propulsion thrust system study. Volume 3: Tradeoff studies of alternate thrust system configurations

Several thrust system design concepts were evaluated and compared using the specifications of the most advanced 30 cm engineering model thruster as the technology base. Emphasis was placed on relatively high power missions. The extensions in thruster performance required for the Halley's comet mission were defined and alternative thrust system concepts were designed in sufficient detail for comparing mass, efficiency, reliability, structure, and thermal characteristics. Confirmation testing and analysis of thruster and power-processing components were performed. A baseline design was selected from the alternatives considered, and the design analysis and documentation were refined. A program development plan was formulated that outlines the work structure considered necessary for developing, qualifying, and fabricating the flight hardware for the baseline thrust system within the time frame of a project to rendezvous with Halley's comet. An assessment was made of the costs and risks associated with a baseline thrust system as provided to the mission project under this plan. Critical procurements and interfaces were identified and defined

The semantic effects of verb raising and its consequences in second language grammars

This article considers whether highly proficient second language speakers of English can distinguish meaning contrasts associated with constructions where there is a raising be, and constructions where there is a non-raising thematic verb, as illustrated in the difference between (1a) and (1b): 1a. Kim is reading a novel (`event-in-progress/existential ? interpretation

Infants Use Prosody to Learn About Clauses

Many researchers have proposed that infants may be able to use prosody to bootstrap into syntax (e.g., Morgan, 1986). Thus far, researchers have shown that prosodic cues are useful for chunking linear sequences, but have not addressed its usefulness in cuing hierarchical syntactic structure. In this study, we asked if infants treat prosodically-marked units as moveable (moveability is a classic test of syntactic constituency). Our results suggest that they do, providing support for the possibility that prosody is a stronger cue to syntactic structure than has previously been shown

Does degradation from selective logging and illegal activities differently impact forest resources? A case study in Ghana

Degradation, a reduction of the ecosystem’s capacity to supply goods and services, is widespread in tropical forests and mainly caused by human disturbance. To maintain the full range of forest ecosystem services and support the development of effective conservation policies, we must understand the overall impact of degradation on different forest resources. This research investigates the response to disturbance of forest structure using several indicators: soil carbon content, arboreal richness and biodiversity, functional composition (guild and wood density), and productivity. We drew upon large field and remote sensing datasets from different forest types in Ghana, characterized by varied protection status, to investigate impacts of selective logging, and of illegal land use and resources extraction, which are the main disturbance causes in West Africa. Results indicate that functional composition and the overall number of species are less affected by degradation, while forest structure, soil carbon content and species abundance are seriously impacted, with resources distribution reflecting the protection level of the areas. Remote sensing analysis showed an increase in productivity in the last three decades, with higher resiliency to change in drier forest types, and stronger productivity correlation with solar radiation in the short dry season. The study region is affected by growing anthropogenic pressure on natural resources and by an increased climate variability: possible interactions of disturbance with climate are also discussed, together with the urgency to reduce degradation in order to preserve the full range of ecosystem functions

Using Historical Interlibrary Loan Data and OCLC to Downsize our Print Journal Collection

In 2014 Wayne State University closed its Science & Engineering Library (SEL) converting the building into a mediated storage collection. In 2017 the University received funding from the State of Michigan to convert the SEL into lab and classroom space intended to support our various STEM programs. This project would have a significant impact on our print journal collection, system wide, due to the 600,000 volumes housed in SEL and the limited available space to absorb them in other parts of the library system. This challenge required a radical downsizing of this collection in the most responsible way possible while minimizing the deleterious impact on faculty and student research. Our starting point was using historical data extracted from our Atlas© Illiad database covering 2010-15, in addition to other data sources. Using historical document delivery and lending data we were able to lay the groundwork for making informed decisions about retention candidates. In order to advance the project we partnered with OCLC’s Sustainable Collection Services (SCS) to provide us with access to our Illiad data, title level holdings in Worldcat to compare our titles to, and the technical expertise needed to clean-up and make sense of the data. As we began work on the project the criteria we considered included: usage, special collection status, completeness of the run held, alternative sources of access, and content issues. From a Collection Development perspective, the main focus of this project has been assuring that the faculty and students will continue to have access to the content of weeded journals and would experience minimum delay between the point of identification and having it in-hand. The goal of this presentation is to demonstrate one of many possible uses of the data currently sitting in various ILL databases that can be used to make data-driven collection management decisions