8 research outputs found

    Regolith Properties of Mercury Derived from Observations and Modelling

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    The properties of Mercury's regolith have been investigated at optical and near-infrared wavelengths with high-resolution imaging, photometric, and spectroscopic observations with the Swedish Vacuum Solar Telescope and the Nordic Optical Telescope. A new global optical map at a spatial resolution of 200 km shows that the well known (from Mariner 10) and poorly known hemispheres are indistinguishable with respect to the distribution, number density, and morphological parameters of bright albedo features. This indicates a globally uniform recent (<3 Gyr) geologic evolution, a compositionally very homogeneous surface and the absence of a lunar-like mare–terrae albedo dichotomy. It is found that the spectrum of Mercury is linear, strongly sloped, lacks detectable absorption features and displays a unique relation between the continuum slope and photometric geometry. Mercury has a photometrically smoother surface than the average near-side Moon, and is 10–15% fainter and 50% more back scattering in the V-band. Unlike the case for the Moon, the average single-particle backscattering anisotropy increases with wavelength. Intimate regolith mixing models are used to determine a probable surface composition of predominantly Ca-rich labradorite plagioclase feldspar with minor low-iron enstatitic orthopyroxene, and rule out high-iron pyroxenes or olivines as other than insignificant constituents. Abundances of FeO ~1.2 wt%, TiO2 ~0 wt%, and submicroscopic metallic iron ~0.1–0.3 wt% are found for the average surface. This implies an optically active grain size of 15–30 μm that is a factor of two smaller than for the Moon. A numerical integration study shows that hermeocentric orbits with semi-major axes <30 mercurian radii for elliptic retrograde, and circular prograde, object are stable for durations in excess of 4.5 Myr. The weak gravitational scattering effect of Mercury indicates that re-impacting particles may have been important for the early evolution of its crust

    Product portfolio management in industrial design : a model of design strategies for mature portfolios

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    To achieve progression in a product portfolio, companies employ industrial designers to aid in the development and creation of new products. Researchers have shown that industrial designers play a consolidating role at both strategic and operational management levels due to the need to incorporate requirements from several company functions, such as brand, research and development, production, economics and senior management. This article investigates how to expand the ways in which a product portfolio may be extended and updated, from an industrial design perspective. Seven product portfolio development strategies were identified. Inspired by studies of competitor's influence on an existing portfolio, a theoretical descriptive model was developed: the Industrial Design Product Portfolio Management model, which positions the suggested product portfolio development strategies in relation to existing and competing products. The findings may advance our current understanding of existing product portfolio management strategies and the connection between management and product design. Thus, it could be a useful framework for academics, teachers and professionals.

    Mercury's surface and composition to be studied by BepiColombo

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    We describe the contributions that we expect the BepiColombo mission to make towards increased knowledge and understanding of Mercury's surface and composition. BepiColombo will have a larger and more capable suite of instruments relevant for determination of the topographic, physical, chemical and mineralogical properties of the surface than carried by NASA's MESSENGER mission. We anticipate that the insights gained into the planet's geological history and its current space weathering environment will enable us to understand the relationships between surface composition and the composition of different types of crust. This will enable estimation of the composition of the mantle from which the crust was derived, and lead to better constraints on models for Mercury's origin and the nature of the material from which it formed
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