Ion engine casing construction and method of making same Patent

Permanently magnetized ion engine casing construction for use in spacecraft propulsion system

Focussing system for an ion source having apertured electrodes Patent

Apertured electrode focusing system for ion sources with nonuniform plasma densit

Self-starting circuit for switching regulators

Schematic is provided on a self-starting circuit for a switching regulator which uses a logic circuit to sense a change in output voltage and provides a correction signal for dc power sources. With this device, the total power consumed by the logic circuitry is held to a minimum, and the circuit receives the optimum regulated supply power

Electron bombardment cesium ion engine system quarterly report, 3 may - 31 jul. 1965

Electron bombardment cesium ion engine - research and developmen

Reconstruction of eolian bed forms and paleocurrents from cross-bedded strata at Victoria Crater, Meridiani Planum, Mars

Outcrop exposures imaged by the Opportunity rover at Victoria Crater, a 750 m diameter crater in Meridiani Planum, are used to delineate sedimentary structures and further develop a dune-interdune depositional model for the region. The stratigraphy at Victoria Crater, observed during Opportunity's partial traverse of its rim, includes the best examples of meter-scale eolian cross bedding observed on Mars to date. The Cape St. Mary promontory, located at the southern end of the rim traverse, is characterized by meter-scale sets of trough cross bedding, suggesting northward migrating sinuous-crested bed forms. Cape St. Vincent, which is located at the opposite end of the traverse, shows tabular-planar stratification indicative of climbing bed forms with meter- to decameter-scale dune heights migrating southward. Promontories located between Cape St. Mary and Cape St. Vincent contain superposed stratigraphic units with northward and southward dipping beds separated by outcrop-scale bounding surfaces. These bounding surfaces are interpreted to be either reactivation and/or superposition surfaces in a complex erg sea. Any depositional model used to explain the bedding must conform to reversing northward and southward paleomigration directions and include multiple scales of bed forms. In addition to stratified outcrop, a bright diagenetic band is observed to overprint bedding and to lie on an equipotential parallel to the preimpact surface. Meter-scale cross bedding at Victoria Crater is similar to terrestrial eolian deposits and is interpreted as a dry dune field, comparable to Jurassic age eolian deposits in the western United States

Electron bombardment cesium ion engine system Summary report, 3 May 1965 - 16 Dec. 1966

Design, development, and life tests of electron bombardment cesium ion engine system, permanent magnet engine, and ac discharge engin

Business model diversification. Demand relatedness, entry sequencing, and curvilinearity in the diversification-performance relationship

This study integrates research on business model diversification (BMD) and demand-side theory to examine the relationship of BMD to performance and the sequencing of business model additions. We begin by explaining and demonstrating that the overall degree of BMD has an inverted U-shaped relationship with firm performance. We next highlight the particular role that demand relatedness plays in BMD. We first provide evidence that the inverted U-shaped relationship flattens in times of financial shocks, consistent with arguments that the benefits of BMD from consumers’ willingness-to-pay for simultaneous use of multiple business models may diminish during shocks. Second, we argue that firms tend to sequence the addition of new business models based on demand relatedness, and we provide evidence that the degree of demand relatedness between a core and a target business model enhances the likelihood of diversification into that target business model

Ion rocket system research and development Final report, 24 Feb. 1964 - 25 Jun. 1965

Design studies and testing of ion rocket engine and zero gravity feed syste

Modelling regional land change scenarios to assess land abandonment and reforestation dynamics in the Pyrenees (France)

International audienceOver the last decades and centuries, European mountain landscapes have experienced substantial transformations. Natural and anthropogenic LULC changes (land use and land cover changes), especially agro-pastoral activities, have directed influenced the spatial organization and composition of European mountain landscapes. For the past 60 years, natural reforestation has been occurring due to a decline in both agricultural production activities and rural population. Stakeholders, to better anticipate future changes, need spatially and temporally explicit models to identiy areas at risk of land change and possible abandonment. This paper presents an integrated approach combining forecasting scenarios and a LULC changes simulation model to assess where LULC changes may occur in the Pyrenees Mountains, based on historical LULC trands and a range of future socio-economic drivers. The proposed methodology considers local specificities of Pyrenan valleys, sub-regional climate and topographical properties, and regional economic policies. Results indicate that some regions are projected to face strong abandonment, regardless of scenario conditions. Overall, high rates of change are associated with administrative regions where land productivity is highly dependent on socio-economic drivers and climatic and environmental conditions limit intensive (agricultural and/or pastoral) production and profitability. The combination of the results for the four scenarios allows assessements of where encroachment (e.g. colonization by shrublands) and reforestation are the most probable. This assessment intends to provide insight into the potential future development of the Pyrenees to help identify areas that are the most sensitive to change and to guide decision makers to help their management decisions