6,281 research outputs found
Flush-mounted dielectric-loaded axial slot on circular cylinder
The theory, computer program, and numerical results of an investigation of an axial slot antenna on a circular cylinder are discussed. The cylinder is partially coated with a dielectric layer and the antenna radiates through a flush mounted window. The study was conducted to determine the effects of a high temperature dielectric layer on the performance of antennas mounted on a space shuttle. Mathematical models are developed to show the relationships of the parameters. Curves are developed to compare the theoretical and actual far field radiation patterns
Mutual impedance of nonplanar-skew sinusoidal dipoles
The mutual impedance of nonplanar-skew sinusoidal dipoles is presented as a summation of several exponential integrals with complex arguments. Mathematical models are developed to show the near-zone field of the sinusoidal dipole. The mutual impedance of coupled dipoles is expressed as the sum of four monopole-mobopole impedances to simplify the analysis procedure. The subroutines for solving the parameters of the dipoles are discussed
Computer analysis of aircraft and shuttle antennas
Progress on predicting the patterns of high-frequency antennas on aircraft and shuttles is reported. Patterns are presented for an axial slot antenna on a circular cylinder partially coated with a dielectric layer. Results are shown for Omega signal disturbance by a conducting vertical pole
Reforestation on the Minnesota National Forest
The Minnesota National Forest was created by an Act of Congress in 1902. It comprises a net area of 197,000 acres. The tract is located at the headwaters of the Mississippi River and aside from an economic standpoint, is valuable as a protection forest and also as a public recreation ·ground. It is known throughout the middle west and even on the Atlantic Coast as the playground of Minnesota. Its many lakes, its excellent beaches and bathing facilities, combined with a stand of virgin white and norway pine, such as can be found nowhere else in the United States, attract many tourists. As a result, during the past four years, two summer hotels have been constructed. In addition, thirty-five summer homes have been built along the lake shores by people from Minnesota, Iowa, North and South Dakota, Nebraska, Missouri, Illinois and even New York
Red Pine on the Minnesota National Forest
The silvicultural system in vogue for red pine on the Minnesota National Forest consists of clear cutting and leaving scattered seed trees. The first timber sale was made in 1904. At that time, five per cent of the entire stand was left in the form of scattered seed trees for reproductive purposes. Through careful investigations and practical observations by the forest officers in charge, it was shown conclusively that five per cent did not leave enough trees over the area to restock the same successfully. Accordingly, it was recommended and later became a law that, thereafter, on all timber sale areas on the Minnesota National Forest, ten per cent of the stand should be left for reforestation purposes. In stands that cut from twenty to twenty-five thousand board feet per acre five per cent of the trees left standing would be abundant; but, in stands of the more scattered and open types, the seed trees were decidedly lacking in number and very sparsely sprinkled over the area. Then, too, five per cent did not leave a great amount of protection for the ground cover, or for the trees themselves. Many blow-downs can be found throughout the timber sale areas
Citizenship, Naturalization, and Asylum: The Case of Britain
Citizenship and naturalization procedures in the UK are examined in historical perspective. Recent legislation is reviewed in the light of global change. The implication of membership in the European Union is examined. The differential treatment of Commonwealth citizens and former colonial subjects is reviewed, as well as human rights questions raised by the treatment of asylum seekers. As a result of globalization, Britain is experiencing the same contradictory forces as other advanced industrial societies. Demographic and economic forces promote immigration, which is resisted for a combination of security fears and ethnocentric attitudes.Cet article examine les procédures pour l’obtention de la citoyenneté et de la naturalisation au Royaume Uni dans une perspective historique. À la lumière de changements qui interviennent au niveau global, il passe en revue les lois adoptées récemment. Il examine aussi les implications de l’adhésion du pays à l’Union Européenne. Il passe ensuite en revue le traitement préférentiel accordéaux citoyens des pays du Commonwealth et des anciennescolonies, ainsi que les questions de droits humains soulevées par le traitement réservé aux demandeurs d’asile. La globalisation expose la Grande Bretagne aux mêmes vents contradictoires qui affectent les autres sociétés industrielles avancées. Les forces démographiques etéconomiques promouvoient l’immigration, alors qu’une combinaison de peurs sécuritaires et d’attitudes ethnocentriques suscite de la résistance
How Will Tobacco Farmers Respond to the Quota Buyout? Findings from a Survey of North Carolina Tobacco Farmers
The tobacco quota buyout is expected to have significant impacts on U.S. tobacco markets, farmers, tobacco-dependent communities, and public health. Using data from four surveys of a panel of North Carolina tobacco farmers conducted between 1997 and 2004, we investigate changing farmer attitudes towards and intentions following a quota buyout.Crop Production/Industries,
Refugees, Inequality, and Human Development
This paper examines the relation between refugee movements and indicators of income, education, and life expectancy in sending and receiving countries. Countries which score low on the Human Development Index are more likely to experience conflict giving rise to internal displacement and refugee movements. Wealthier countries accept the better educated for permanent settlement, while admitting less skilled manual workers and asylum seekers on a temporary basis.Cet article examine les relations entre les mouvements de réfugiés et les indicateurs de revenus, l’éducation et l’espérance de vie dans les pays de départ et les pays d’accueil. Les pays avec un score bas sur l’Indice du développement humain ont le plus de probabilité de connaître des confl its provoquant des déplacements internes et des mouvements de réfugiés. Les pays plus riches acceptent les mieux éduqués pour l’établissement permanent, tout en admettant les travailleurs manuels moins éduqués ainsi que les demandeurs d’asile sur une base temporaire
Global Apartheid: A Postscript
Trends in the numbers and location of refugees and asylum seekers during the 1980s and the 1990s are compared. The question of whether the world has created a system of “global apartheid” is reviewed. The outcome of asylum applications filed in European countries is compared with those in Canada and the United States. It is concluded that racism still prevails in the treatment of refugees. Canada’s record compares favourably with those of other developed countries, although the main burden of refugee protection still falls on less developed regions of the world.Cet article compare les tendances contenues dans le nombre et la localisation géographique de réfugiés et de demandeurs d’asile pendant toute la période des années 80 et 90. Il passe en revue la question de savoir si notre monde a crée un système d’« apartheid global ». Il compare aussi les suites données aux demandes d’asile soumises dans des pays européens et celles soumises au Canada et aux États-Unis. La conclusion tirée est que le racisme prévaut toujours dans le traitement réservé aux réfugiés. La performance du Canada se compare favorablement avec celle d’autres pays développés, bien que le gros du fardeau de la protection des réfugiés pèse toujours sur les régions les moins développées du monde
- …