1,389 research outputs found
Gossamer roadmap technology reference study for a solar polar mission
No full textA technology reference study for a solar polar mission is presented. The study uses novel analytical methods to quantify the mission design space including the required sail performance to achieve a given solar polar observation angle within a given timeframe and thus to derive mass allocations for the remaining spacecraft sub-systems, that is excluding the solar sail sub-system. A parametric, bottom-up, system mass budget analysis is then used to establish the required sail technology to deliver a range of science payloads, and to establish where such payloads can be delivered to within a given timeframe. It is found that a solar polar mission requires a solar sail of side-length 100 – 125 m to deliver a ‘sufficient value’ minimum science payload, and that a 2. 5μm sail film substrate is typically required, however the design is much less sensitive to the boom specific mass
Interview With P.C. Hodgell
No full textP.C. Hodgell, author of God Stalk and Dark of the Moon, was one of the many authors who attended Mythcon XIX in Berkeley last summer. She was good enough to meet with the Mythic Circle writers\u27 roundtable and share some of her experiences with us. The following is transcribed from a low-quality tape; when it was possible to recognize a speaker’s voice I have identified them - others are noted as ct. Hope you enjoy it
POLAR investigation of the Sun—POLARIS
No full textThe POLAR Investigation of the Sun (POLARIS) mission uses a combination of a gravity assist and solar sail propulsion to place a spacecraft in a 0.48 AU circular orbit around the Sun with an inclination of 75° with respect to solar equator. This challenging orbit is made possible by the challenging development of solar sail propulsion. This first extended view of the high-latitude regions of the Sun will enable crucial observations not possible from the ecliptic viewpoint or from Solar Orbiter. While Solar Orbiter would give the first glimpse of the high latitude magnetic field and flows to probe the solar dynamo, it does not have sufficient viewing of the polar regions to achieve POLARIS’s primary objective: determining the relation between the magnetism and dynamics of the Sun’s polar regions and the solar cycle
Numerical studies of ion reflection in collisionless theta-pinch implosions using a hybrid Vlasov-fluid model
No full textNonequilibrium and classical dissipation scalings in DNS of homogeneous isotropic decaying turbulence
No full textWe present data from direct numerical simulations of homogeneous isotropic decaying turbulence showing both the non-equilibrium and the classical dissipation scalings reported in wind-tunnel experiments of both regular and fractal grid-generated turbulence, i.e. Cε ∼ (Re0/Reλ)n with n of order unity and Cε ∼ constant, respectively (Re0 and Reλ are global and local Reynolds numbers). These two dissipation behaviours lead to different power-law decay exponents in both regimes also in accord with the experiments. Finally, we show that in both regimes the maximum non-linear energy cascade flux, Π, reasonably satisfies the classical expectation that Π ∼ K3/2/l
Reinforcing glass with glass: Application of transport reinforcement in structural glass beams
No full textDue to the increasing demand of transparency in buildings, it is no longer unusual to apply transparent elements into the bearing structure. Glass is a strong but very brittle material, which means safety is rather problematic should it break. Safety is an issue that has to be improved before glass can be considered suitable for structural elements. Earlier studies have shown that reinforcing glass beams will provide reasonable residual load-bearing capacity, which could provide this safety. Glass fibre is suitable as reinforcement material when the transparency is regarded as important. In February 2009 at the Faculty of Architecture at Delft University of Technology, P.C. Louter designed and tested a laminated glass beam with embedded glass fibre rods. The bonding interlayer consisted of SentryGlas foil, developed by DuPont and often applied for lamination in hurricane-resistant windows. The results were promising and the concept showed high potential for further research. The study of this thesis project is focussed on improving the concept of embedding reinforcement in laminated glass beams.Design and ConstructionCivil Engineering and Geoscience
Scientific Payload for an Interstellar Probe Mission
No full textNASA's Interstellar Probe Mission will be the first spacecraft specifically designed to explore the outer solar system, pass through the boundaries of the heliosphere, and sample the nearby interstellar medium. During the spring of 1999, NASA's Interstellar Probe Science and Technology Definition Team* developed a concept for a mission that will travel to 200- 400 AU using solar-sail propulsion. The principal scientific goals would be to explore the outer solar system, explore the structure of the heliosphere and its interaction with the interstellar medium, and explore the nature of the interstellar medium itself. These studies
would be carried out by a -150 kg spacecraft carrying a scientific payload designed to make comprehensive measurements of heliospheric and interstellar plasma, fields, energetic particles, neutral gas, and dust. We discuss the scientific goals and strawman payload for this
mission
Foreign Direct Investment. The key determinants of foreign direct investment in Poland. Case company: ArgusPack P.C.
No full textThe aim of this thesis was to provide a better understanding of the determinants of foreign direct invest-ment (referred to hereafter as “FDI”). The company ArgusPack P.C. is a flexible packaging manufacturer located in Greece which decided to engage using FDI in Poland. Thus, the factors that favors FDI into the selected region had to be determined.
This thesis was a qualitative research, an empirical non-numerical data research. For primary data a series of interviews was conducted by the author and for secondary data peer-reviewed articles and literatures that fully-describe the determinants of FDI were utilized. There are numerous theories that define the FDI, such as Vernon’s product life cycle (Vernon, 1966), Buckley and Casson’s internalization theory (P. Buckley, 1976) and Dunning’s eclectic paradigm (Dunning J. , 2001). In this project, the Dunning’s eclectic paradigm theory was selected and applied, aiming to provide a better understanding of the factors that motivates a company or an organization to become involved using FDI. Through a research study the primary data were collected and through excessive academic research the secondary data were collected as well. In conclu-sion, an analysis of the primary data in combination with the secondary data was done mainly focusing on the participants’ point of view and the way it aligns with the theoretical aspect given by this thesis. In the end a conclusion and recommendation were formed based on all data mentioned and the personal belief of the author.
Finally, since the key determinants have been identified and examined. Foreign direct investment seems to be an adequate business strategy for ArgusPack P.C. in Polan
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