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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Developmental history of European beachgrass (Ammophila arenaria (L.) Link) plantings on the Oregon coastal sand dunes /

Green, Diantha Louise. January 1965 (has links)
Thesis (M.S.)--Oregon State University, 1965. / Typescript. Includes bibliographical references (leaves 47-50). Also available on the World Wide Web.
82

Performance analysis of the MULTISAFE protection enforcement processes /

Deaver, Mason C. January 1983 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1983. / "Supported, in part, by the National Science Foundation under Grant Number MCS-7903936."--Leaf iii. Vita. Abstract. Includes bibliographical references (leaves 143-145). Also available via the Internet.
83

The characteristics of user-generated passwords /

Sawyer, Darren A. January 1990 (has links) (PDF)
Thesis (M.S. in Information Systems)--Naval Postgraduate School, March 1990. / Thesis Advisor(s): Zviran, Moshe ; Haga, William J. "March 1990." Description based on signature page as viewed on October 21, 2009. DTIC identifier(s): Access control, passwords, computer security, identification verification. Author(s) subject terms: Passwords, computer security, user-generated passwords, informaiton system security. Includes bibliographical references (p. 98-99). Also available online.
84

The effects of the in duplum rule and clause 103(5) of the National Credit Bill 2005 on interest /

Vessio, Monica L. January 2005 (has links)
Thesis, LLM--University of Pretoria, 2005. / Includes bibliographical references. Available on the Internet via the World Wide Web.
85

Développement et formulations de produits solaires conditionnés sous forme d'aérosol

Durand, Laurence 25 May 2010 (has links)
L’exposition au soleil, et donc aux rayons ultraviolets, est de plus en plus fréquente chez l’homme dans les pays occidentaux. En effet, les modes de vie ont fortement changé ces dernières années, avec pour résultat une augmentation non négligeable des loisirs en extérieur. Ceci a pour conséquence une augmentation de l’apparition des cancers cutanés, dont le pronostic de survie est souvent mauvais et l’issue fatale. De plus, les traitements associés à ces maladies sont lourds et n’agissent pas toujours de façon efficace. Les campagnes d’information et de prévention face aux dangers du soleil restent donc les principales mesures efficaces pour lutter contre le cancer cutané lié à une surexposition au soleil. La recherche de nouveaux produits permettant de protéger de manière efficace la peau des effets néfastes des rayons UV reste donc un défi permanent et primordial pour la recherche dans l’industrie cosmétique. Dans un premier temps, le travail a consisté à développer des nouvelles formulations de produits solaires contenant des concentrations élevées en filtres UV, conditionnées sous forme d’aérosol, celles-ci valables pour le marché européen. Une émulsion E/H et une émulsion E/Si ont donc été réalisées. Elles contenaient au final 27% de filtres UV pour l’émulsion E/H et 16,5% de filtres UV pour l’émulsion E/Si, dont 4% de filtres inorganiques pour les deux types d’émulsion. Leur viscosité était de 6800 mPa.s pour l’émulsion E/H et de 2800 mPa.s pour l’émulsion E/Si. Ces formulations étaient stables lorsqu’elles étaient conservées pendant 2 mois à 40°C et également lorsqu’elles subissaient 5 cycles de température entre 5°C et 40°C. La mise en aérosol de ces émulsions a nécessité l’utilisation de 22% de gaz propulseur (mélange : butane, propane, isobutane). La taille des gouttelettes étant un paramètre important de la caractérisation des aérosols pour le choix des matériaux à utiliser ainsi que pour sécurité afin d’éviter toute inhalation pulmonaire, l’influence de différents éléments sur celle-ci a été étudiée. Nous avons ainsi montré que la concentration en gaz, la viscosité, la présence ou non de filtres inorganiques ainsi que le choix des valves et diffuseurs utilisés jouent un rôle dans la taille des gouttelettes émises, celle-ci ne pouvant pas être inférieure à 30 µm de diamètre. La taille des gouttelettes émises était supérieure à 50 µm avec pas plus de 0.1% ayant une taille inférieure à 10 µm et maximum 25% des gouttelettes ayant une taille comprise entre 10 et 30 µm. Les produits formulés contenaient de grandes quantités en filtres solaires, organiques et inorganiques (27% pour l’émulsion E/H et 16,6% pour l’émulsion E/Si), il était donc important de vérifier qu’aucun des filtres présents dans les émulsions ne passaient à travers la peau lors de l’application des produits solaires. En effet, ceux-ci doivent rester à la surface de l’épiderme afin de maintenir l’efficacité des produits solaires et d’éviter des effets néfastes systémiques éventuels en pénétrant la peau. Une étude in vitro utilisant de la peau humaine excisée et des cellules de diffusion de Franz nous a permis de constater que les filtres inorganiques présents dans les formulations restaient en surface de la peau, et seulement deux des filtres organiques (l’EMC et MBBT) présentaient un potentiel de pénétration cutanée négligeable et non nocif pour la santé humaine (maximum 1,21 µg/ml/cm2 pour EMC et maximum 0,14 µg/ml/cm2 pour MBBT). De plus, après 24 h d’expérience, plus de 50% des filtres restaient à la surface de la peau, ce qui permettait de maintenir l’efficacité des produits solaires. Afin de mener à bien cette étude, des méthodes analytiques pour l’analyse simultanée des filtres solaires organiques d’une part, par CLHP (Chromatographie Liquide Haute Performance), et inorganiques d’autre part, par ICP-OES (Inductively Coupled Plasma - Optical Emission Spectrometry), ont été mises au point et validées. Une étude in vivo non invasive, basée sur le prélèvement des couches successives du stratum corneum, a été réalisée par la suite. Cette dernière a été effectuée par la méthode du « tape stripping », qui utilise des disques adhésifs rigides, et sur 9 volontaires pendant une période de 8 h. Elle a permis de confirmer les résultats obtenus avec la méthode in vitro. Une bonne corrélation entre ces deux types d’étude a été observée. Enfin, la dernière partie du travail a porté sur l’EMC, un des filtres organiques utilisé dans la plupart des produits solaires mis sur le marché et dans les émulsions E/H et E/Si formulées. Ce filtre présente une sensibilité à la lumière et aux rayons UV. L’encapsulation lipidique de celui-ci a donc été envisagée afin de produire des nanoparticules dont la matrice lipidique a pour but de protéger l’EMC contre une dégradation causée par les rayons UV. Trois lipides différents ont été investigués et ont montré des résultats positifs de protection vis-à-vis des rayonnements UV. En effet, après 2 h d’irradiation par les UV, une perte d’efficacité de 30% de l’EMC pur a été observée contre 10% à 21% pour l’EMC encapsulé par les différents lipides. De plus, les nanoparticules n’ont pas montré de potentiel d’augmentation de pénétration cutanée de l’EMC.
86

A Spatial Analysis of the Impact of Development on Wetland Habitat in Mount Pleasant, South Carolina

Medlin, Jenna 01 April 2004 (has links)
In response to growing concerns over wetland habitat loss and the associated impact on water resources, federal and state legislation has been enacted to protect vulnerable wetland habitats from the impacts of humans. In order to examine the efficacy of current coastal resource policy and its implementation, a study was conducted in Mount Pleasant, South Carolina, a coastal city of the Atlantic, focusing on the quantification of wetland habitat change over time within a specific area of interest. The study incorporated an assessment of the effects of escalating population pressures and subsequent urban development on local wetland habitats due to the inherent threat of habitat degradation resulting from negligent development practices. The research methodology included a series of stakeholder interviews conducted within the Mount Pleasant community in order to define the key players who shape coastal resource policy formation, implementation, and enforcement. Further, a spatial analysis examined land use change over time. A historical record of regional land use derived from remotely sensed satellite imagery enabled the measurement of land use change over time. The results of a change detection analysis indicate an acceleration of wetland habitat loss in the second decade chosen for analysis in spite of strengthened coastal resource regulations enacted within the same time period. These results support a need for improved regulatory enforcement strategies and utilization of conservation-driven development practices.
87

Water Quality Assessment in Cypress Creek Nature Preserve

Flora, Jason 01 May 2003 (has links)
Swamps are unique ecological communities that provide many valuable ecosystem services. In Kentucky, however, many swamps were altered by cypress removal and land development in their watersheds. Cypress Creek Swamp, which lies near Paducah in western Kentucky, is a good example of a swamp whose ecological integrity may be threatened by past and current nearby land use practices. This study was conducted to assess the water quality and macro- and microinvertebrate communities in the swamp. Three sites were monitored for temperature, dissolved oxygen, pH, specific conductivity, depth, phosphorus measured as orthophosphate, nitrite (NO2") and nitrate (NO3", NOx collectively), and ammonia nitrogen (NH3). The temperature, dissolved oxygen, NH3 and NOx concentrations changed with the growing season, but pH demonstrated little variability among the sites. The specific conductivity and phosphorus levels were highly variable. Principal component analysis (PCA) indicated no significant difference in microinvertebrate taxa identified among locations or through time. A oneway analysis of variance (ANOVA) indicated no significant difference in macroinvertebrate population total densities between locations (P = 0.847), and a oneway analysis of variance (ANOVA) showed no significant difference in microinvertebrate population total densities among locations (P = 0.153) or through time (P = 0.294). As development continues in the watershed, this work provides an important baseline for future water quality monitoring in the preserve.
88

The Progression of Recycling in Bowling Green, Kentucky

Marklin, Susan 01 December 2001 (has links)
Recycling is an important issue when dealing with solid waste. It keeps many tons of garbage out of our landfills and prolongs landfill life. Although many people in the Bowling Green area participate in the mandatory recycling program, there are still many who do not. The number of people who participate in the program has steadily grown over the past five years; however, there are still many people who need to get involved. This research argues that much effort has been put into recycling in recent years at the global, national, and local level. However, it also argues that even more remains to be done, especially at the local level. I have conducted a sixty-day field study of both commercial and residential sites in the Bowling Green area. This field study shows that everyday there are many recyclables as well as other items placed into the trash that need not go into our garbage. This field study will also show that there are some very wasteful industries in Bowling Green. They are throwing food items away that could be used to help hungry people in the Bowling Green vicinity. It will also show that some industries, such as Houchens Markets, throw recyclables such as cardboard into their dumpster even though they have a cardboard bailer on the premises. This research will also offer reasons for people choosing not to use the recycling program. I have conducted a survey of one hundred people who live in the Bowling Green area. This survey shows that one reason some people do not use the recycling program is that they feel they are forced to do it. A few people went so far as to say that they feel the recycling program is a form of communism, and they will not use the program for that reason. I have also included entire matrices from both the residential and commercial study areas. These matrices list every item that I found during this field study. I have also included some recommendations for increased participation in the recycling program, as well as some suggestions for the industries as to how they could dispose of their unwanted food items and help the general public at the same time. I wish people could see the Earth the way that I see it. If they could, they wouldn't even think about recycling: it would become a part of their everyday routine.
89

Environmentalism in the United States: An Evolving Perspective

Snow, Mary 01 May 1996 (has links)
The purpose of this study is to investigate environmentalism in the United States. The dimension of perspective receives considerable attention. The prevailing perspective by a society regarding the importance of the health of the natural world greatly influences the degree of support of environmental organizations, environmental policy, as well as the direction charted for the future of that society. The perspectives of the Native Americans and the dominant European cultures which arrived in North America are presented and contrasted. It is supposed that the perspective which prevails in the United States regarding the importance of the natural world is evolving. During the eighteenth and nineteenth centuries, Manifest Destiny and the American Industrial Revolution exacted a steep cost from the nation's natural resources. Previously perceived as "raw materials," today the unmanipulated environment is viewed in terms of its recreational, aesthetic, ecologic, and spiritual worth. This evolving perspective is demonstrated qualitativelythrough case studies featuring methods of sustainable agriculture, by an ecological restoration project, and by grassroots eco-poltical activism. The changing perspective is quantified by measuring the growth of some of the nation's leading environmental organizations. It is hypothesized that those organizations have experienced significant growth over the study period, or from 1980-1994. It is concluded that there has been phenomenal growth of the leading environmental organizations during the study period. The prevailing perspective by the citizens of the United States is indeed evolving toward a view that is more sustainable since the missions of the nation's leading environmental organizations are endorsed by the financiers of those organizations Environmentalists, now more than ever, must remain encouraged and vigilant in order to increase the chances that the newly evolved perspective will become policy. Increased participation in the political process is facilitated by the personal computer which allows both the monitoring of environmental voting records of the individual Members of Congress while making those legislators accessible by electronic mail systems. Finally, the optimal sustainable perspective is reflected in the words of Ralph Waldo Emerson. Each step toward the ultimate environmental perspective indicates genuine progress for America.
90

Ecology, Economy and Ecotourism: Sustaining People and the Environment

Snow, Richard 01 May 1996 (has links)
Tourism is the world's largest industry. The fastest growing segment of the travel and tourist trade is ecotourism. The concept of sustainable development insists that humans cooperate with nature in the search for an ecological economy which can support present and future populations. Ecotourism attempts to attain this elusive goal by preserving ecosystems while generating revenue for local communities. In this study, the researcher examines the positive and negative effects of ecotourism on people, culture, and landscape. An analysis of tourism data seems to suggest that developing countries, which are popular ecotour destinations, are benefitting economically and ecologically from properly planned ecotourism.

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