The X-15/HL-20 operations support comparison

During the 1960's, the United States X-15 rocket-plane research program successfully demonstrated the ability to support a reusable vehicle operating in a near-space environment. The similarity of the proposed HL-20 lifting body concept in general size, weight, and subsystem composition to that of the X-15 provided an opportunity for a comparison of the predicted support manpower and turnaround times with those experienced in the X-15 program. Information was drawn from both reports and discussions with X-15 program personnel to develop comparative operations and support data. Based on the assumption of comparability between the two systems, the predicted staffing levels, skill mix, and refurbishment times of an operational HL-20 appear to be similar to those experienced by the X-15 for ground support. However, safety, environmental, and support requirements have changed such that the HL-20 will face a different operating environment than existed at Edwards during the 1950's and 1960's. Today's operational standards may impose additional requirements on the HL-20 that will add to the maintenance and support burden estimate based on the X-15 analogy

A space transportation system operations model

Presented is a description of a computer program which permits assessment of the operational support requirements of space transportation systems functioning in both a ground- and space-based environment. The scenario depicted provides for the delivery of payloads from Earth to a space station and beyond using upper stages based at the station. Model results are scenario dependent and rely on the input definitions of delivery requirements, task times, and available resources. Output is in terms of flight rate capabilities, resource requirements, and facility utilization. A general program description, program listing, input requirements, and sample output are included

Global sensitivity analysis of an end-to-end marine ecosystem model of the North Sea : factors affecting the biomass of fish and benthos

Comprehensive analysis of parameter and driver sensitivity is key to establishing the credibility of models of complex systems. This is especially so for models of natural systems where experimental manipulation of the real-world to provide controlled validation data is not possible. Models of marine ecosystems fall into this category, but despite the interest in these models for evaluating the effects of climate change and fishing on nutrient fluxes and the abundances of flora and fauna, none have yet been subjected to global sensitivity analysis. Here we present results of both local ‘one-at-a-time’ (OAT), and variance based global sensitivity analyses (GSA) of the fish and fishery aspects of StrathE2E, an end-to-end (nutrients to birds and mammals) ecosystem model of the North Sea. The sensitivity of the model was examined with respect to internal biological parameters, and external drivers related to climate and human activity. The OAT Morris method was first used to screen for factors most influential on model outputs. The Sobol GSA method was then used to calculate quantitative sensitivity indices. The results indicated that the fish and shellfish components of the model (demersal and pelagic fish, filter/deposit and scavenge/carnivore feeding benthos) were influenced by different sets of factors. Harvesting rates were directly influential on demersal and pelagic fish biomasses. Suspension/deposit feeding benthos were directly sensitive to changes in temperature, while the temperature acted indirectly on pelagic fish through the connectivity between model components of the food web. Biomass conversion efficiency was the most important factor for scavenge/carnivorous feeding benthos. The results indicate the primacy of fishing as the most important process affecting total fish biomass, together with varying responses to environmental factors which may be relevant in the context of climate change. The non-linear responses and parameter interactions identified by the analysis also highlight the necessity to use global rather than local methods for the sensitivity analysis of ecosystem models

Eco-rational conversion: spheres of influence into spheres of transformation - creating an ecological society

Professor Douglas Morris, Educational Foundations & Policy Studies - Eco-rational conversion: spheres of influence into spheres of transformation - creating an ecological societ

A study of certain factors in the illegitimately pregnant women known to the North Shore Children's Friend Society and three other private agencies; with an estimate of whether these agencies are serving all those who need help.

Thesis (M.S.)--Boston Universit

River transport 1189-1600

The purpose of this thesis is to establish the extent of river transportation in the period 1189 - 1600. Investigation is made as to which rivers were physically usable, which were legally usable and the comparative cost of land and river transport. The evidence of historic use is examined and these records are compared with the recent limits of use of the rivers. Hence an estimate is made as to which sections of rivers were probably used during that period. The principles of fluvial geomorphology have been used to estimate past channel changes. The legal records have been studied and analysed. Considerable evidence of the use of rivers has been found which materially increases the lengths of rivers for which there are records of historic use. It is concluded that:- 1. all rivers which were physically usable were legally usable, 2. there is a high probability that each section of a river which is now physically usable was usable by small boats in the period 1189-1600, 3. on the balance of probabilities each section of a river which is now physically usable was used during that period. Finally the implication of this research for the present day law relating to public access on rivers is considered

Exploding lakes in Vanuatu - "Surtseyan-style" eruptions witnessed on Ambae Island

After a long silence, Lake Vui on Ambae Island burst into spectacular life on the 28th of November 2005, disrupting the lives of 10 000 inhabitants on this sleepy tropical island in the SW Pacific. "Surtseyan- style" explosions burst through the Island's summit lake waters forming a new tuff-cone and threatening to form deadly lahars or volcanic floods. Such eruptions are rarely well observed, and these fleeting opportunities provide a chance to match volcanic processes with rock-sequences found commonly in the geologic recor