11,283 research outputs found
Compression Waves and Phase Plots: Simulations
Compression wave analysis started nearly 50 years ago with Fowles.[1]
Coperthwaite and Williams [2] gave a method that helps identify simple and
steady waves. We have been developing a method that gives describes the
non-isentropic character of compression waves, in general.[3] One result of
that work is a simple analysis tool. Our method helps clearly identify when a
compression wave is a simple wave, a steady wave (shock), and when the
compression wave is in transition. This affects the analysis of compression
wave experiments and the resulting extraction of the high-pressure equation of
state
The Calm Before the Storm? - Anticipating the Arrival of General Purpose Technologies
This paper presents a Schumpeterian quality-ladder model incorporating the impact of new General Purpose Technologies (GPTs). GPTs are breakthrough technologies with a wide range of applications, opening up new innovational complementarities. In contrast to most existing models which focus on the events after the arrival of a new GPT, the model developed in this paper focuses on the events before the arrival if R&D firms know the point of time and the technological impact of this drastic innovation. In this framework we can show, that the economy goes through three main phases: First, the economy is in its old steady state. Second, there are transitional dynamics and finally, the economy is in a new steady state with higher growth rates. The transitional dynamics are characterized by oscillating cycles. Shortly before the arrival of a new GPT, there is an increase in R&D activities and growth going even beyond the old steady state levels and immediately before the arrival of the new GPT, there is a large slump in R&D activities using the old GPT.Schumpeterian growth, research and development, general purpose technologies
Long-Term Growth Driven by a Sequence of General Purpose Technologies
We present a Schumpterian model of endogenous growth with General Purpose Technologies (GPTs) that captures two important historical stylized facts: First, from the beginning of mankind until today GPTs are arriving at an increasing frequency and, second, all GPTs heavily depended on previous technologies. In our model, the arrival of GPTs is endogenous and arises stochastically depending on the currently available applied knowledge stock. This way of endogenizing the arrival of new GPTs allows for a model which is more in tune with the historical reality than the existing GPT models.Schumpeterian growth; research and development; general purpose technologies
Community Response Strategies for Environmental Problems of Water Supply and Wastewater Disposal in Fairbanks, Alaska
This report examines the history of the response strategies of the
Fairbanks, Alaska, community to problems of water supply and wastewater
disposal. Fairbanks is significant since it is the largest settlement in
the northern subarctic and arctic regions of North America. Today, the
City of Fairbanks and the surrounding urban area have a combined population
of over 40,000
Environmental quality conditions in Fairbanks, Alaska, 1972
Published by
The Institute of Water Resources
and
The Institute of Social, Economic and Government Research
Fairbanks, AlaskaThis study represents a starting point for investigating the nature and interconnectivity of environmental quality problems in Fairbanks in the 1970's. Since the Fairbanks flood of 1967, no
detailed survey of environmental quality conditions has been conducted despite the impact of the flood, the considerable
expansion of the city limits, and the population expansion (anticipated and actual) associated with the oil pipeline.
The study focuses on selective aspects of environmental quality of continuing and increasing concern to Fairbanks area residents and also to the city and borough governments. Specifically, the issues
analyzed are (1) the environmental setting of the area, (2) structures, especially housing conditions, (3) premise conditions, and (4) waste control.
Much of the data was derived from a program called NEEDS, an acronym for Neighborhood Environmental Evaluation and Decision
System. NEEDS was developed by the Bureau of Community Environmental Management of the Department of Health, Education, and Welfare for rapid gathering of environmental, health,
and social information in urban areas.1 The NEEDS survey design consists of two separate stages. Stage I is concerned with collecting
general environmental quality information to determine geographically where the most pronounced environmental health problems exist in a given urban area. Stage II consists of detailed interviews with residents of the identified "problem areas" to determine the exact nature of existing health and environmental problems, e.g., housing, health, availability of services, and attitudes regarding existing government (local, state, and federal) programs.
With this information, local officials could begin to reorganize existing programs and/or develop new programs to solve some of the
interrelated environmental quality problems in the disadvantaged sections of their cities.The work upon which this report is based was
supported by funds provided by the State of
Alaska, the University of Alaska at Fairbanks, the United States Public Health Service, and the Office of Water Research and Technology
Effect of an oxygen plasma on uncoated thin aluminum reflecting films
Thin aluminum films were considered for use as a reflective surface for solar collectors on orbiting solar dynamic power systems. A matter of concern is the durability of such reflective coatings against oxidative attack by highly reactive neutral atomic oxygen, which is the predominate chemical specie in low Earth orbit. Research to date was aimed at evaluating the protective merit of thin dielectric coatings over the aluminum or other reflective metals. However, an uncoated aluminum reflector may self-protect by virtue of the oxide formed from its exposed surface, which constitutes a physical barrier to further oxidation. This possibility was investigated, and an attempt was made to characterize the effects of atomic oxygen on thin Al films using photomicrographs, scanning electron microscopy, spectrophotometry, Auger analysis, and mass measurements. Data collected in a parallel effort is discussed for its comparative value. The results of the investigation of uncoated aluminum supported the self-protection hypothesis, and importantly, it was found that long term specular reflectance for uncoated aluminum exceeded that of Al and Ag reflectors with dielectric coatings
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