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At least 235 records · Page 13

New technology applied to telemedicine

Satellite communications technology was used for establishing international telemedicine communications links in a number of instances, (e.g., Telemedicine SpaceBridge between Armenia and the United States in 1989, and the proposed linkages shown, for demonstration during this conference and during 1992 and 1993). In the current example, geostationary satellites are used to provide intercontinental communications links between the two countries and also for distribution within each country.

Miller, Edward F.↗

Preliminary analysis of thermal-infrared multispectral scanner data of the Iron Hill, Colorado carbonatite-alkalic rock complex

The Iron Hill carbonatite-alkalic igneous rock complex is in the Powderhorn mining district, approximately 40 km south-southwest of Gunnison, Colorado. The complex, which occupies about 30 sq km, was emplaced in metasedimentay and metavolcanic rocks during the later Precambrian or early Cambrian. The main rock types in the complex, from oldest to youngest, are fenite, pyroxenite, uncompahgrite, ijolite, nepheline syenite, and dolomitic carbonatite. The carbonatite is limonitic and forms an elliptially shaped 4 sq km stock. Calcitic and dolomitic carbonatite dikes are also numerous throughout the complex and in the pre-existing rocks. Pyroxenite is the most widespread rock type within the complex, but pyroxene is extensively altered to biotite, phlogopite, and vermiculite. Fenite, which formed through Na, K-metasomatism of the country rocks, typically contains more feldspar and less quartz than the equivalent unaltered country rocks. The other alkalic rock types are less widespread and less well exposed. Parts of the complex are covered by Oligocene ash-flow tuff and alluvial, colluvial, and glacial deposits. Sagebrush and grass cover is moderately dense to very dense at low to intermediate elevations; coniferous tree cover is dense at high elevations and on some north-facing slopes at lower elevations. A new algorithm was used to compute spectral emissivity ratios, independent of any emissivity assumptions. This algorithm has the advantage that any of the possible emissivity ratios can be computed and, thus, a large variety of composite ratio images can be constructed, which permits examination of various geologic hypotheses based on the spectral properties of the surface materials.

Rowan, Lawrence C.↗

Worldwide survey of direct-to-listener digital audio delivery systems development since WARC-1992

Each country was allocated frequency band(s) for direct-to-listener digital audio broadcasting at WARC-92. These allocations were near 1500, 2300, and 2600 MHz. In addition, some countries are encouraging the development of digital audio broadcasting services for terrestrial delivery only in the VHF bands (at frequencies from roughly 50 to 300 MHz) and in the medium-wave broadcasting band (AM band) (from roughly 0.5 to 1.7 MHz). The development activity increase was explosive. Current development, as of February 1993, as it is known to the author is summarized. The information given includes the following characteristics, as appropriate, for each planned system: coverage areas, audio quality, number of audio channels, delivery via satellite/terrestrial or both, carrier frequency bands, modulation methods, source coding, and channel coding. Most proponents claim that they will be operational in 3 or 4 years.

Messer, Dion D.↗

RF optics study for DSS-43 ultracone implementation

The Ultracone feed system will be implemented on DSS 43 to support the S-band (2.3 GHz) Galileo contingency mission. The feed system will be installed in the host country's cone, which is normally used for radio astronomy, VLBI, and holography. The design must retain existing radio-astronomy capabilities, which could be impaired by shadowing from the large S-band feed horn. Computer calculations were completed to estimate system performance and shadowing effects for various configurations of the host country's cone feed systems. Also, the DSS-43 system performance using higher gain S-band horns was analyzed. A new S-band horn design with improved return loss and cross-polarization characteristics is presented.

Lee, P.↗

Regional climates in the GISS general circulation model: Surface air temperature

One of the more viable research techniques into global climate change for the purpose of understanding the consequent environmental impacts is based on the use of general circulation models (GCMs). However, GCMs are currently unable to reliably predict the regional climate change resulting from global warming, and it is at the regional scale that predictions are required for understanding human and environmental responses. Regional climates in the extratropics are in large part governed by the synoptic-scale circulation and the feasibility of using this interscale relationship is explored to provide a way of moving to grid cell and sub-grid cell scales in the model. The relationships between the daily circulation systems and surface air temperature for points across the continental United States are first developed in a quantitative form using a multivariate index based on principal components analysis (PCA) of the surface circulation. These relationships are then validated by predicting daily temperature using observed circulation and comparing the predicted values with the observed temperatures. The relationships predict surface temperature accurately over the major portion of the country in winter, and for half the country in summer. These relationships are then applied to the surface synoptic circulation of the Goddard Institute for Space Studies (GISS) GCM control run, and a set of surface grid cell temperatures are generated. These temperatures, based on the larger-scale validated circulation, may now be used with greater confidence at the regional scale. The generated temperatures are compared to those of the model and show that the model has regional errors of up to 10 C in individual grid cells.

Hewitson, Bruce↗

United Nations/European Space Agency Workshops on Basic Space Science

In 1958, the United Nations (UN) formally recognized a new potential for international cooperation by establishing an ad hoc Committee on the Peaceful Uses of Outer Space (COPUOS). A year later the Committee became a permanent body, and by 1983 membership had expanded to 53 states, with more than half of the members coming from the developing world. In 1970, COPUOS established the UN Program on Space Applications in order to strengthen cooperation in space science and technology between non-industrialized and industrialized countries. In the last few years, the UN and its COPUOS have paid increasing attention to education and research in space science and technology, including basic space science. In 1991 the UN, in cooperation with ESA, initiated the organization of annual Workshops in Basic Space Science for developing countries. These Workshops are designed to be held in one of the following major regions: Asia and the Pacific, Latin America and the Caribbean, Africa, Western Asia, and Europe. Accordingly, Basic Space Science Workshops have already been held in India (1991), Costa Rica andColombia (1992), and Nigeria (1993). The fourth Workshop was held from 27 June to 1 July 1994 at the Cairo University, in Egypt, for Western Asia.

Haubold, H. J.↗

Improving regional health care in West Africa using current space systems and technology

This paper discusses the issues involved with establishing an integrated satellite health network in West Africa based on currently available technology. The system proposed makes use of a central national facility capable of transmitting and receiving voice/data and video signals from the entire country. Regional, field and local facilities provide timely epidemiologic information, sharing of medical expertise through telemedical consultations, enhance optimized resource distribution and build a framework for telecommunications for the entire country.

Jemison, Mae C.↗

Cross-cultural attitudes of flight crew regarding CRM

This study asks if the Cockpit Management Attitude Questionnaire (CMAQ) can detect differences across countries, and/or across occupations. And if so, can those differences be interpreted? Research has shown that the CMAQ is sensitive to attitude differences between and within organizations, thereby demonstrating its effectiveness with American populations. But the CMAQ was originally designed by American researchers and psychometrically refined for American pilots. The items in the questionnaire, though general in nature, still reflect the ubiquitous Western bias, because the items were written by researchers from and for the one culture. Recognizing this constraint, this study is nonetheless interested in attitudes toward crew behavior, and how those attitudes may vary across country and occupation.

Merritt, Ashleigh↗

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 55: Career goals and educational preparation of aerospace engineering and science students: An international perspective

Results are presented of a survey of aerospace engineering and science students conducted in India, Japan, Russia, the United Kingdom, and the United States. The similarities and differences among aerospace engineering and science students from the five countries are examined in the context of two general aspects of educational experience. First, the extent to which students differ regarding the factors that led to the choice of a career in aerospace, their current levels of satisfaction with that choice, and career-related goals and objectives is considered. Second, the importance of certain communications/information-use skills for professional use is examined, as well as the frequency of use and importance of specific information sources and products to meet students' educational needs. Overall, the students who participated in this research remain relatively happy with the choice of a career in aerospace engineering, despite pessimism in some quarters about the future of the industry. Regardless of national identity, aerospace engineering and science students appear to share a similar vision of the profession in terms of their career goals and aspirations. The data also indicate that aerospace engineering and science students are well aware of the importance of communications/information-use skills to professional success and that competency in these skills will help them to be productive members of their profession. Collectively, all of the students appear to use and value similar information sources and products, although some differences appear by country.

Pinelli, Thomas E.↗

Update on the Fire (solar probe) mission study

Since mid-1994 the U.S. and Russia have been studying the technical feasibility of a joint solar probe mission as part of the 'Fire and Ice' concept to explore close to the Sun, and Pluto, together. In the current concept of the 'Fire' mission, separate spacecraft built by each country would be launched together, fly by Jupiter to shed orbital angular momentum and achieve a solar polar orbit, and arrive 3.6 years later at 4 and 10 R(sub s). The Fire mission would measure basic parameters of the modes of energy and momentum flow and transfer to the coronal plasma that are not observable remotely. Specifically, measurement of magnetic fields, waves, suprathermal particles, and critical features of the plasma particle composition and distribution function would be made from 4 to 30 R(sub s) where the solar wind is known to be accelerated. In addition, the Fire spacecraft should image coronal structures unambiguously and relate the underlying and flown-through structures to plasma characteristics measured in situ. Each country is developing a backup plan to pursue the solar probe objectives alone if the other side is unable to carry out its mission.

Jones, W. Veron↗

An Interdisciplinary Undergraduate Space Physics Course: Understanding the Process of Science Through One Field's Colorful History

Science education in this country is in its greatest period of ferment since the post-Sputnik frenzy a generation ago. In that earlier time, however, educators' emphasis was on producing more scientists and engineers. Today we recognize that all Americans need a good science background. The ability to observe, measure, think quantitatively, and reach logical conclusions based on available evidence is a set of skills that everyone entering the workforce needs to acquire if our country is to be competitive in a global economy. Moreover, as public policy increasingly crystallizes around scientific issues, it is critical that citizens be educated in science so that they may provide informed debate and on these issues. In order to develop this idea more fully, I proposed to teach a historically based course about space physics as an honors course at the University of Maryland-College Park (UMCP). The honors program at UMCP was established to foster broad-based undergraduate courses that utilize innovative teaching techniques to provide exemplary education to a select group of students. I designed an introductory course that would have four basic goals: to acquaint students with geomagnetic and auroral phenomena and their relationship to the space environment; to examine issues related to the history of science using the evolution of the field as an example; to develop familiarity with basic skills such as describing and interpreting observations, analyzing scientific papers, and communicating the results of their own research; and to provide some understanding of basic physics, especially those aspect that play a role in the near-earth space environment.

Lopez, Ramon E.↗

Radar Monitoring of Wetlands for Malaria Control

Malaria is perhaps the most serious human disease problem. It inflicts millions worldwide and is on the rise in many countries where it was once under control. This rise is in part due to the high costs, both economic and environmental, of current control programs. The search for more cost-effective means to combat malaria has focussed attention on new technologies, one of which is remote sensing. Remote sensing has become an important tool in the effort to control a variety of diseases worldwide and malaria is perhaps one of the most promising. This study is part of the malaria control effort in the Central American country of Belize, which has experienced a resurgence of malaria in the last two decades. The proposed project is a feasibility study of the use of Radarsat (and other similar radar systems) to monitor seasonal changes in the breeding sites of the anopheline mosquito, which is responsible for malaria transmission. We propose that spatial and temporal changes in anopheline mosquito production can be predicted by sensing where and when their breeding sites are flooded. Timely knowledge of anopheline mosquito production is a key factor in control efforts. Such knowledge can be used by local control agencies to direct their limited resources to selected areas and time periods when the human population is at greatest risk. Radar is a key sensor in this application because frequent cloud cover during the peak periods of malaria transmission precludes the use of optical sensors.

Pope, Kevin O.↗

Proposed Wind Turbine Aeroelasticity Studies Using Helicopter Systems Analysis

Advanced systems for the analysis of rotary wing aeroelastic structures (helicopters) are being developed at NASA Ames by the Rotorcraft Aeromechanics Branch, ARA. The research has recently been extended to the study of wind turbines, used for electric power generation Wind turbines play an important role in Europe, Japan & many other countries because they are non polluting & use a renewable source of energy. European countries such as Holland, Norway & France have been the world leaders in the design & manufacture of wind turbines due to their historical experience of several centuries, in building complex wind mill structures, which were used in water pumping, grain grinding & for lumbering. Fossil fuel cost in Japan & in Europe is two to three times higher than in the USA due to very high import taxes. High fuel cost combined with substantial governmental subsidies, allow wind generated power to be competitive with the more traditional sources of power generation. In the USA, the use of wind energy has been limited mainly because power production from wind is twice as expensive as from other traditional sources. Studies conducted at the National Renewable Energy Laboratories (NREL) indicate that the main cost in the production of wind turbines is due to the materials & the labor intensive processes used in the construction of turbine structures. Thus, for the US to assume world leadership in wind power generation, new lightweight & consequently very flexible wind turbines, that could be economically mass produced, would have to be developed [4,5]. This effort, if successful, would result in great benefit to the US & the developing nations that suffer from overpopulation & a very high cost of energy.

Ladkany, Samaan G.↗

General Public Space Travel and Tourism: Executive Summary - Volume 1

Travel and tourism is one of the world's largest businesses. Its gross revenues exceed $400 billion per year in the U.S. alone, and it is our second largest employer. U.S. private sector business revenues in the space information area now approximate $10 billion per year, and are increasing rapidly. Not so in the human spaceflight area. After spending $100s of billions (1998 dollars) in public funds thereon, and continuing to spend over $5 billion per year, the government is still the only customer for human spaceflight goods and services. Serious and detailed consideration was first given to the possibility of space being opened up to trips by the general public three decades ago, and some initial attempts to do so were made a dozen years ago. But the difficulties were great and the Challenger disaster put an end to them. In recent years professional space tourism studies have been conducted in the United Kingdom, Germany and, especially, Japan. In the U.S., technological progress has been pronounced; we have had nearly a decade's experience in seeing our astronauts travel to-from low Earth orbit (LEO) safely, and we expect to commence assembly of a LEO space station housing a half-dozen people this year. Too, NASA and our space industry now have new and promising space transportation development programs underway, especially the X-33 and X-34 programs, and some related, further generation, basic technology development programs. And five private companies are also working on the design of new surface - LEO vehicles. The first professional space tourism market studies have been conducted in several countries in the past few years, especially in Japan and here. The U.S. study makes it clear that, conceptually, tens of millions of us would like to take a trip to space if we could do so with reasonable safety, comfort and reliability, and at an acceptable price. Initial businesses will address the desires of those willing to pay a greater price and accept a greater risk. A two-year cooperative Space Act agreement study has been conducted by our National Aeronautics and Space Administration and the Space Transportation Association. It was conducted by NASA and STA study leaders drawing upon the competence, experience and hard-nosed imagination of a national Steering Group and scores of attendees at a multi-day Workshop. The study has involved scores of professionals and business people from various areas: astronauts; space booster technology and operations professionals; a hotel architect and a hotel operator; an airline planner; insurance underwriters; space sickness experts; space theme park designers; space and travel and tourism association and business executives; a space-related financier; university tourism and space policy experts; present and former space-responsible government officials; space entrepreneurs; space writers; This study concludes that serious national attention should now be given to activities that would enable the expansion of today's terrestrial space tourism businesses, and the creation of in-space travel and tourism businesses. Indeed, it concludes that, in time, it should become a very important part of our Country's overall commercial and civil space business-program structure.

ONeil, Daniel↗

A Seasonal Air Transport Climatology for Kenya

A climatology of air transport to and from Kenya has been developed using kinematic trajectory modeling. Significant months for trajectory analysis have been determined from a classification of synoptic circulation fields. Five-point back and forward trajectory clusters to and from Kenya reveal that the transport corridors to Kenya are clearly bounded and well defined. Air reaching the country originates mainly from the Saharan region and northwestern Indian Ocean of the Arabian Sea in the northern hemisphere and from the Madagascan region of the Indian Ocean in the southern hemisphere. Transport from each of these source regions show distinctive annual cycles related to the northeasterly Asian monsoon and the southeasterly trade wind maximum over Kenya in May. The Saharan transport in the lower troposphere is at a maximum when the subtropical high over northern Africa is strongly developed in the boreal winter. Air reaching Kenya between 700 and 500 hPa is mainly from Sahara and northwest India Ocean flows in the months of January and March, which gives way to southwest Indian Ocean flow in May and November. In contrast, air reaching Kenya at 400 hPa is mainly from southwest Indian Ocean in January and March, which is replaced by Saharan transport in May and November. Transport of air from Kenya is invariant, both spatially and temporally, in the tropical easterlies to the Congo Basin and Atlantic Ocean in comparison to the transport to the country. Recirculation of air has also been observed, but on a limited and often local scale and not to the extent reported in southern Africa.

Gatebe, C. K.↗

Workshop on Extraterrestrial Materials from Cold and Hot Deserts

Since 1969 expeditions from Japan, the United States, and European countries have recovered more than 20,000 meteorite specimens from remote ice fields of Antarctica. They represent approximately 4000-6000 distinct falls, more than all non-Antarctic meteorite falls and finds combined. Recently many meteorite specimens of a new "population" have become available: meteorites from hot deserts. It turned out that suitable surfaces in hot deserts, like the Sahara in Africa, the Nullarbor Plain in Western and South Australia, or desert high plains of the U.S. (e.g., Roosevelt County, New Mexico), contain relatively high meteorite concentrations. For example, the 1985 Catalog of Meteorites of the British Museum lists 20 meteorites from Algeria and Libya. Today, 1246 meteorites finds from these two countries have been published in MetBase 4.0. Four workshops in 1982, 1985, 1988, and 1989 have discussed the connections between Antarctic glaciology and Antarctic meteorites, and the differences between Antarctic meteorites and modern falls. In 1995, a workshop addressed differences between meteorites from Antarctica, hot deserts, and modem falls, and the implications of possible different parent populations, infall rates, and weathering processes. Since 1995 many more meteorites have been recovered from new areas of Antarctica and hot deserts around the world. Among these finds are several unusual and interesting specimens like lunar meteorites or SNCs of probable martian origin. The Annual Meeting of the Meteoritical Society took place in 1999 in Johannesburg, South Africa. As most of the recent desert finds originate from the Sahara, a special workshop was planned prior to this meeting in Africa. Topics discussed included micrometeorites, which have been collected in polar regions as well as directly in the upper atmosphere. The title "Workshop on Extraterrestrial Materials from Cold and Hot Deserts" was chosen and the following points were emphasized: (1) weathering processes, (2) terrestrial ages, (3) investigations of "unusual" meteorites, and (4) collection and curation.

Schultz, Ludolf↗

Workshop on Extraterrestrial Materials from Cold and Hot Deserts

Since 1969 expeditions from Japan, the United States, and European countries have recovered more than 20,000 meteorite specimens from remote ice fields of Antarctica. They represent approximately 4000-6000 distinct falls, more than all non-Antarctic meteorite falls and finds combined. Recently many meteorite specimens of a new "population" have become available: meteorites from hot deserts. It turned out that suitable surfaces in hot deserts, like the Sahara in Africa, the Nullarbor Plain in Western and South Australia, or desert high plains of the U.S. (e.g., Roosevelt County, New Mexico), contain relatively high meteorite concentrations. For example, the 1985 Catalogue of Meteorites of the British Museum lists 20 meteorites from Algeria and Libya. Today, 1246 meteorites finds from these two countries have been published in MetBase 4.0. Four workshops in 1982, 1985, 1988, and 1989 have discussed the connections between Antarctic glaciology and Antarctic meteorites, and the differences between Antarctic meteorites and modem falls. In 1995, a workshop addressed differences between meteorites from Antarctica, hot deserts, and modem falls, and the implications of possible different parent populations, infall rates, and weathering processes. Since 1995 many more meteorites have been recovered from new areas of Antarctica and hot deserts around the world. Among these finds are several unusual and interesting specimens like lunar meteorites or SNCs of probable martian origin. The Annual Meeting of the Meteoritical Society took place in 1999 in Johannesburg, South Africa. As most of the recent desert finds originate from the Sahara, a special workshop was planned prior to this meeting in Africa. Topics discussed included micrometeorites, which have been collected in polar regions as well as directly in the upper atmosphere. The title "Workshop on Extraterrestrial Materials from Cold and Hot Deserts" was chosen and the following points were emphasized: (1) weathering processes, (2) terrestrial ages, (3) investigations of "unusual" meteorites, and (4) collection and curation.

Schultz, Ludolf↗

Tunable Dielectric Materials and Devices for Broadband Wireless Communications

Wireless and satellite communications are a rapidly growing industries which are slated for explosive growth into emerging countries as well as countries with advanced economies. The dominant trend in wireless communication systems is towards broadband applications such as multimedia file transfer, video transmission and Internet access. These applications require much higher data transmission rates than those currently used for voice transmission applications. To achieve these higher data rates, substantially larger bandwidths and higher carrier frequencies are required. A key roadblock to implementing these systems at K-band (18-26.5 GHz) and Ka-band (26.5-40 GHz) is the need to develop hardware which meets the requirements for high data rate transmission in a cost effective manner. In this chapter, we report on the status of tunable dielectric thin films for devices, such as resonators, filters, phased array antennas, and tunable oscillators, which utilize nonlinear tuning in the control elements. Paraelectric materials such as Barium Strontium Titanate ((Ba, Sr)TiO3) have dielectric constants which can be tuned by varying the magnitude of the electric field across the material. Therefore, these materials can be used to control the frequency and/or phase response of various devices such as electronically steerable phased array antennas, oscillators, and filters. Currently, tunable dielectric devices are being developed for applications which require high tunability, low loss, and good RF power-handling capabilities at microwave and millimeter-wave frequencies. These properties are strongly impacted by film microstructure and device design, and considerable developmental work is still required. However, in the last several years enormous progress has occurred in this field, validating the potential of tunable dielectric technology for broadband wireless communication applications. In this chapter we summarize how film processing techniques, microwave test configurations, and prototype devices have combined to drive the field to its current stage of development.

Mueller, Carl H.↗