Ground-to-orbit laser propulsion: Advanced applications

Laser propulsion uses a large fixed laser to supply energy to heat an inert propellant in a rocket thruster. Such a system has two potential advantages: extreme simplicity of the thruster, and potentially high performance, particularly high exhaust velocity. By taking advantage of the simplicity of the thruster, it should be possible to launch small (10 to 1000 kg) payloads to orbit using roughly 1 MW of average laser power per kg of payload. The incremental cost of such launches would be of an order of $200/kg for the smallest systems, decreasing to essentially the cost of electricity to run the laser (a few times$10/kg) for larger systems. Although the individual payload size would be smaller, a laser launch system would be inherently high-volume, with the capacity to launch tens of thousands of payloads per year. Also, with high exhaust velocity, a laser launch system could launch payloads to high velocities - geosynchronous transfer, Earth escape, or beyond - at a relatively small premium over launches to LEO. The status of pulsed laser propulsion is briefly reviewed including proposals for advanced vehicles. Several applications appropriate to the early part of the next century and perhaps valuable well into the next millennium are discussed qualitatively: space habitat supply, deep space mission supply, nuclear waste disposal, and manned vehicle launching

A Comparison of Laser and Microwave Approaches to CW Beamed Energy Launch

One approach to beamed energy propulsion uses a solid heat exchanger to absorb energy from a distant source and transfer it to a working fluid. Systems of this type can be designed using either microwave or laser sources. In general, microwave sources have been expected to be less expensive than lasers for a given power, but to be more limited in range and/or energy density. With the development of high power millimeter-wave sources and low-cost diode laser arrays, both assumptions are open to question. In this paper, we compare current and projected microwave and laser source technologies for a 100-kilogram-class ground-to-orbit launch system and identify key issues affecting the system-level trade between the two approaches

MEDIATION IN THE NORWEGIAN LAND CONSOLIDATION COURTS

In Norway land consolidation is organized entirely within the judicial system. This paper describes how land consolidation courts work, and examines mediation activities in the courts. Questionnaires were used to get data on 727 cases in 1996, and in-depth interviews with 23 judges were used to get information on mediation behavior. The results indicate that mediation is a frequent activity. Many cases are settled through mediation rather than by verdicts. Mediation activities vary with case type, complexity, significance and conflict level. Mediation activities reduce conflicts even in those cases where final decisions are made through verdicts. Cases that have a mediated settlement are generally less complex, less significant and have lower conflict levels than cases ending with verdicts. Judges use a large number of mediation techniques, and there are large variations in mediation styles between judges. The results are discussed in terms of future research needs and in terms of the practice of mediation in land disputes.Consolidation of land holdings -- Law and legislation -- Norway, Agricultural courts and procedure -- Norway, Mediation -- Norway, Land conflicts -- Norway, Land Economics/Use,

A COMPARATIVE STUDY OF LAND TENURE, PROPERTY BOUNDARIES, AND DISPUTE RESOLUTION: EXAMPLES FROM BOLIVIA AND NORWAY

This paper compares and contrasts patterns of land tenure, property boundaries, and dispute resolution regarding property using examples from two diverse social and economic regions: Bolivia and Norway. The goal of the paper is essentially a comparative one. By placing the examples of Bolivia and Norway side by side, the authors hope to shed light on common strategies while recognizing the diversity to be found in the ways that people relate to land. It is hoped that readers will be able to compare the material here with examples from other regions. By using data based on field research and related methods from two regions starkly distinguished from each other by language, socioeconomic levels, political histories, and extent of integration into world markets, the authors present a picture of how people interact with their bounded environments and the various meanings that they construct through such environments. Norway has one of the highest standards of living in the world and is in many ways a model of economic and social efficiency; Bolivia, by contrast, is characterized by extreme ecological zones and has struggled for most of its 170 years of independence to both maintain its population at the most basic of levels and to achieve social stability. Yet, despite these significant historical and contemporary differences, the ways in which people relate to land in both countries are often remarkably similar, particularly in rural areas.Land tenure -- Bolivia, Land tenure -- Norway, Dispute resolution -- Bolivia, Dispute resolution -- Norway, Land conflicts -- Bolivia, Land conflicts -- Norway, Land Economics/Use,

The social imaginary, Jacques Lacan, and the African Christian diaspora in Europe

This thesis is a theoretical discussion that brings together three major fields of enquiry. It is structured in two sections. In Part One, the notion of the social imaginary, as a theoretical response to the challenges of 'multiple modernities', is compared to the theories of the psychoanalyst Jacques Lacan. In Part Two, the findings from this comparison are applied to reflect on contemporary issues in Christianity in and out of Africa. The notion of the social imaginary represents a way of addressing issues of society through the lens of the subject's imagination, instead of thinking of society as external and bounded. Lacan helps us to ground this approach in a psychological appraisal of the subject, whereby the subject is 'lacking' and the external world functions as a source of identification and cognition that serves to cover up this void. This perspective allows us to re-think 'imagination' in terms of signification as, for Lacan, the writing of the self hinges on the subject's appropriation of signifiers. Similarly, the social imaginary could be understood in terms of the subject's assembly of images. The twist, for Lacan, is that the meaning ( signified) of the signifier can never be finally determined, which raises fundamental questions about the production of knowledge and the coherence of the social-ideological reality. This traumatic gap in the signifying chain is what Lacan's enigmatic order of the Real is about, and its repression requires from the subject a response that oscillates between thought and affect. Following Slavoj Zizek, we can develop a Lacanian parallel to the social imaginary around the notion of the master-signifier that 'quilts' the production of meaning and anchors our social reality. Crucially, it does so by producing 'objects' that address the subject's desire on the level of cognition as well as enjoyment, of thought and affect. The notion of the master-signifier provides an appealing approach to examine the Charismatic Christian revival taking place in Africa. Taking Ghana as example, I argue that this 'prosperity' -themed awakening could be understood as a response to a context in which symbolic and material voids converge to create a deficit of meaning in the postcolony. The effects of these developments also spill into Africa's 'new' diaspora in Europe, where African-led churches represent an intriguing test-case for a Lacanian reading of 'multiple modernities'. A central point emerging from this analysis is that the diaspora context requires quilting operations that halt not only the sliding of the signified, but of the signifier as such. This analysis could also be read as an indirect contribution to the debate on the significance of the African Christian diaspora in Europe, especially in the light of the idea of 'reverse mission'. In this regard, this thesis urges one to note the changing outlooks of African Christianity from the African continent to Europe, reflecting the changing and expanding psychological needs of its adherents

Current Reforms in Soviet Foreign Trade: With Special Reference to Western Europe

The purpose of this thesis is to analyse the reform-process undertaken by the present Soviet leadership in order to expand the foreign trade with Western Europe. The economic, political and bureaucratic aspects are treated separately

An aircraft noise study in Norway

An extensive study of aircraft noise is currently being conducted in Oslo, Norway. The traffic at Oslo Airport Fornebu that includes both national and international flights, totals approximately 350 movements per day: 250 of these are regular scheduled flights with intermediate and large size aircraft, the bulk being DC9 and Boeing 737. The total traffic during the summer of 1989 was expected to resemble the maximum level to which the regular traffic will increase before the new airport can be put into operation. The situation therefore represented a possibility to study the noise impact on the communities around Fornebu. A comprehensive social survey was designed, including questions on both aircraft and road traffic noise. A random sample of 1650 respondents in 15 study areas were contacted for an interview. These areas represent different noise levels and different locations relative to the flight paths. The interviews were conducted in a 2 week period just prior to the transfer of charter traffic from Gardemoen to Fornebu. In the same period the aircraft noise was monitored in all 15 areas. In addition the airport is equipped with a permanent flight track and noise monitoring system. The noise situation both in the study period and on an average basis can therefore be accurately described. In August a group of 1800 new respondents were subjected to identical interviews in the same 15 areas, and the noise measurement program was repeated. Results of the study are discussed