Canadian development and commercialization of a North American mobile satellite service

Canada recognized early the value of mobile satellite communications, originally through the planning of a military system and subsequently through the development of the Canadian Mobile Satellite (MSAT) systems. Acting on behalf of the government, the Department of Communications (DOC) defined and carried out a complete plan for the implementation of Mobile Satellite Services (MSS). Based on an extensive dialogue between government, industry, and users and encompassing all technical, economic regulatory, and institutional aspects, this plan resulted in the completion by 1986 of a comprehensive business plan and a decision for commercial MSS delivery. The Canadian lead for a commercial system was quickly followed by others, and in particular the U.S., giving rise to the concept of North American MSS

Economic returns and risks to investment in education: An application of the multifactor CAPM

Considering the investment in education as uncertain financial decision making we modify the short-cut method of calculating rates of return to education by incorporating the risk premium. Recognizing that market risk isn't the only factor affecting returns, we estimate the returns to education in fifteen member - states of the European Union and the Organisation for Economic Co-operation and Development during the period 2005 2007 as seen from a macroeconomic point of view using Multifactor CAPM. Following this model we assess, except market risk, the impact of three key macroeconomic variables (investments, productivity and unemployment) on returns and, using panel data regression techniques, we investigate whether this holds true with respect to investment in education. We also evaluate the risk - adjusted performance of investment in education and the role of returns as well as that of the key macroeconomic variables to economic development. The results tend to confirm the theoretical expectations and empirical literature. The purpose of the present study is twofold: first, to estimate the relationship between education returns and risk and second to measure the impact of return and key macro factors on real GDP growth rate, therefore casting light in the channels through which the economicgrowth can be affected

Strain-stiffening in random packings of entangled granular chains

Random packings of granular chains are presented as a model polymer system to investigate the contribution of entanglements to strain-stiffening in the absence of Brownian motion. The chain packings are sheared in triaxial compression experiments. For short chain lengths, these packings yield when the shear stress exceeds a the scale of the confining pressure, similar to packings of spherical particles. In contrast, packings of chains which are long enough to form loops exhibit strain-stiffening, in which the effective stiffness of the material increases with strain, similar to many polymer materials. The latter packings can sustain stresses orders-of-magnitude greater than the confining pressure, and do not yield until the chain links break. X-ray tomography measurements reveal that the strain-stiffening packings contain system-spanning clusters of entangled chains.Comment: 4 pages, 4 figures. submitted to Physical Review Letter

Sub-national TIMES model for analyzing regional future use of Biomass and Biofuels in France and Sweden

International Energy Workshop : http://www.kth.se/polopoly_fs/1.64178!Paper_B4_Forsell.pdfInternational audienceIn the context of mitigating climate change and increase energy security, the utilization of biomass in the energy sector is expected to play a major role. However, to estimate the possibility of fulfilling national goals concerning the future use of biomass sources and to estimate the future use of biomass sources in the energy sector, the current energy system models needs to be further developed to consider the high sub-national variances in the supply and cost of the biomass sources. In this paper we present a sub-national MARKAL/TIMES model for estimating regional utilization of biomass sources and the future development of the energy system. The proposed model is evaluated for two case studies, France and Sweden, for which the future utilization of biomass is evaluated utilizing numerous scenarios of the potential supply of biomass, cost of biomass, and end-use demand. Our results show that the limit of national biomass potentials for energy purposes in France is approximately 35 Mtoe, while all demand scenarios for Sweden could be fulfilled by national biomass potentials. Furthermore, the results show that there are large differences in the regional utilization level of biomass sources, even when the total utilization level of biomass sources is high

Integrated supply of stemwood and residual biomass to forest-based biorefineries

The demand for forest biomass as raw material for a wide range of products in the developing bioeconomy is expected to increase. Along with a constant pressure on forestry to increase its productivity, this development has led to the search for new procurement methods and new assortments. The present study assessed innovative supply chain practices, with a particular focus on the integrated supply of stemwood and residual tree parts. The assortments considered included tree sections, long tops, saw logs with stump cores and small whole trees from thinnings. The assessment included geographically explicit modelling of the supply chain operations and estimation of supply cost and energy use for three industrial locations in Northern Sweden. The innovative supply chains were compared to conventional, separate, harvest of stemwood and logging residues. We conclude that integrated harvest of tops and branches with stemwood assortments, as well as whole-tree harvest in early thinnings, has a significant potential to reduce the supply cost for the non-stemwood assortments. Stump wood generally remains the most expensive assortment. The energy use analysis confirms earlier research showing that the energy input is relatively small compared to the energy content of the harvested feedstock

Distribution, characteristics and potential of biomass-dense thinning forests in Sweden

Understanding the characteristics of unutilized biomass resources, such as small-diameter trees from biomass-dense thinning forests (BDTF) (non-commercially-thinned forests), can provide important information for developing a bio-based economy. The aim of this study was to describe the areal distribution, characteristics (biomass of growing stock, tree height, etc.) and harvesting potential of BDTF in Sweden. A national forest inventory plot dataset was imported into a geographical information system and plots containing BDTF were selected by applying increasingly stringent constraints. Results show that, depending on the constraints applied, BDTF covers 9-44% (2.1-9.8 M ha) of the productive forest land area, and contains 7-34% of the total growing stock (119-564 M OD t), with an average biomass density of 57 OD t ha^-1. Of the total BDTF area, 65% is located in northern Sweden and 2% corresponds to set-aside farmlands. Comparisons with a study from 2008 indicate that BDTF area has increased by at least 4% (about 102 000 ha), in line with general trends for Sweden and Europe. Analyses revealed that the technical harvesting potential of delimbed stemwood (over bark, including tops) from BDTF ranges from 3.0 to 6.1 M OD t yr^-1 (7.5 to 15.1 M m^3 yr^-1), while the potential of whole-tree harvesting ranges from 4.3 to 8.7 M OD t yr^-1 (10.2 to 20.6 M m3 yr^-1) depending on the scenario considered. However, further technological developments of the harvest and supply systems are needed to utilize the full potential of BDTF