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

The cost of closed terminals in the supply chain for a potential biorefinery in northern Sweden

Establishment of biorefineries for processing forest biomass in the Nordic region is extremely costly due to the high investment, running, and procurement costs. Procurement costs could be reduced by allowing all actors to open access to all available terminals in an area (regardless of ownership) and allowing trucks with higher gross weight. These impacts of changes were evaluated for deliveries of logging residue and energy wood chips to a potential biorefinery, from two suppliers in northern Sweden. Open access to all terminals reduced the terminal-procurement costs by 2-6% and the terminal-to-biorefinery transportation costs by 7-9%. When 74 tonnes trucks were used instead of 60 tonnes, the terminal-to-biorefinery transportation costs were reduced by 4 and 3%, in the current situation and with open access to terminals, respectively. However, the largest effect of open access was that the fraction of short-distance transportation to terminals and train transportation from terminals increased significantly. This indicated that open access to terminals and relatively heavy trucks between terminals and the biorefinery are preferable from both environmental and economic perspectives. Furthermore, the estimated cost saving was adequate and should allow the deliverers to pay a reasonable fee for the use of terminal space

Opportunity cost of several methods for determining forest biomass terminal locations in Northern Sweden

Long distance transportation of forest biomass is often unavoidable because the biomass is dispersed over large land areas. This is a problem that limits the development of biorefineries all over the world. The use of biomass terminals where forest biomass is transported to, stored, processed (mostly by mobile machinery), and reloaded can facilitate more environmentally friendly and efficient transportation to a biorefinery. The challenge is to identify the locations that should be selected for terminal establishment in order to minimize the cost of biomass procurement. In this study, locations for terminal establishment are proposed based on an optimization method (Combopt) that simultaneously minimizes the harvesting, transportation, and terminal costs for round wood and logging residues. The outcome of this method was compared with several other methods imitating situations with limited knowledge to estimate potential opportunity costs of potential knowledge deficiency when selecting terminal locations. The results of the Combopt method suggest that six terminals are required in order to minimize the overall cost of satisfying the estimated demand from the biorefineries. The opportunity cost of alternative terminal selection methods ranged from 3.1 to 35.4 million SEK (0.5-6.1% of total procurement cost). Methods that considered biomass relatively close to terminals had lower opportunity costs, together with methods minimizing transportation and terminal cost for the most common wood assortment. The methods and results could be applicable in other parts of the world were similar problems exists in forestry and other industries

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

Forecasting Future Procurement Potential of Swedish Forest Biomass Using Forest Inventory Data

In the last 20 years the use of forest biomass for energy production and sawlog and pulpwood production has increased by 68%, 11% and 31% in Sweden. As Sweden is trying to achieve net zero greenhouse gas emissions by 2045, the high demand for biomass can also be expected in future. Therefore, a method to project the amount of spatially available biomass assortments for industries was developed. Available amounts of different forest assortments were estimated and visualised in a web-based tool using forest inventory data and nationwide projection analyses of available biomass for 2035–2039. In this interval, the greatest amount of available biomass and roundwood will be in Northern Sweden. Results also indicate that already existing harvesting intensity is very high compared to the available biomass in the future. The industry can expect noticeably more available biomass in the coming 100 year period. With increased competition between large pulp mills and biorefineries, the supply areas can exceed 200 km to satisfy raw material demand. The long distance and high volume supply chain requirements will demand further improvement in transportation solution nationally and cross-border in the Baltic Sea Region

Fuel Consumption In Forwarders

Forwarder fuel consumption was studied by examining a total of 27 forwarders under field conditions. Three datasets, representing different data acquisition methods, were used. In a field study, time and fuel consumption by work-element of two 20-21 tonne forwarders in final felling were recorded. In a questionnaire survey, daily data concerning fuel consumption, productivity and average extraction distance was provided on 18 forwarders, divided between final felling and thinning. Finally, accounting data on fuel consumption for 11 forwarders were obtained. In the field study, the fuel consumption varied between 8.3 to 15.7 l/PMH (productive machine hour) for different work elements. The total fuel consumption was 0.28-0.36 l/m3sub (solid under bark) at average extraction distances on 360-412 m for loads of sawlogs and 0.43-0.66 l/m3sub (458-514 m) for loads of pulpwood. 61-62% of that fuel was consumed during loading and driving during loading. The forwarders consumed 0.23-0.38 l/100 m driving and the difference was only 10% with and without load. In the questionnaire survey, the fuel consumption averaged 0.62 l/m3sub (sawlogs and pulpwood, 318 m average extraction distance) for final felling (16-20 tonne forwarders) and 0.92 l/m3sub (644 m) for thinning (11-14 tonnes). An exception was 2.5 tonne forwarders that consumed only 0.35-0.37 l/m3sub (120-180 m). 89% of the extracted volume in the accounting data was from thinnings and the fuel consumption was in average 0.67 l/m3sub (100-200 m) for 9 to11 tonne forwarders. More difficult terrain conditions, the use of tracks and wheel-chains and one more assortment in the questionnaire survey are the most probable reasons for higher fuel consumption than in the field study. At long extraction distances it is especially important to utilize the maximum load capacity to benefit low fuel consumption on m3 basis

Fuel, Hydraulic Oil and Lubricant Consumption in Swedish Mechanized Harvesting Operations, 1996

When subjecting forest products to certification the total environmental load of wood harvesting machinery should also be assessed. In this study fuel, hydraulic oil and lubricant consumption in harvesting operations in Sweden has been examined by using machine data acquired through a questionnaire. The objectives of the study were to assess the contractor and forest company owned harvesters' and forwarders' average oil consumption in practical harvesting operations in Sweden, ascertain if the ownership and size of the machines give different consumption figures and estimate the use of environmentally acceptable hydraulic oils as well as the amount of oil spilled outdoors. Diesel consumption was found to be 935 l/1000 m3ub for forwarders and 1 167 l/1000 m3ub for single-grip harvesters. Hydraulic, transmission and chainsaw oil consumption was significantly higher in forest company owned harvesters while no significant differences were observed among forwarders. Hydraulic oil spillage was estimated for both harvesters and forwarders at 20 l/1000 m3ub. For felling and crosscutting trees a further 35 l/1000 m3ub of chainsaw oil is spilled. Ninety percent of the utilized hydraulic oil was environmentally compatible

Attitudes towards bilingualism : the case of two Greek islands

Bilingualism, and more recently plurilingualism, is attracting considerable attention due to the increasing influx of people with different ethnolinguistic background to Western societies as well as the fact that we live in a globalised world. This study presents the results of a large-scale survey administered to 1,727 students enrolled in Greek schools in the islands of Rhodes and Symi during the scholastic year 2002-2003. Using an adapted version of Baker’s questionnaire (see Baker, 2001), the study attempted to investigate students’ attitudes toward bilingualism. The results indicate a general positive attitude toward bilingualism. Most of the students were aware of the fact that knowing more than one language would be useful in their adult life, particularly in view of the professional and economic rewards that this brings in an increasingly globalised world. It was however found that the subjects of the study were not so positively disposed toward bilingualism as a societal phenomenon. The study findings are discussed in relation to language education policy in Greece.peer-reviewe