Fogwater Harvesting has been demonstrated to be able to provide water for small rural communities in arid and semi-arid regions. Fog droplets coalesce on mesh screens and flow by gravity into a supply network. The technology is simple and can be maintained and managed by the users. The challenge is identifying suitable communities, environmental conditions and ensuring the system meets user demand sustainably. Following the First International Conference on Fog and Fog Collection (19-24 July 1998), a general project cycle for fogwater harvesting for domestic water supply is proposed and discussed. Methodologies and examples are reviewed and placed in an interdisciplinary project framework.

No description available.

Thesis (M.S.) - United States Naval Postgraduate School, 1966. / Bibliography: p. 45-52.

No description available.

L’objet de cette thèse est la conception d’un lidar dédié à la mesure du profil du contenu en eau liquide dans le brouillard. Actuellement, ce paramètre n’est mesuré que sur des volumes restreints, au sol ou à des altitudes données. Or sa connaissance devrait apporter une meilleure compréhension de l’évolution du brouillard et devrait aussi constituer une information intéressante pour le contrôle des modèles de prévision du phénomène. Elle est en théorie possible, car il a été montré à la fin des années 70 qu’il existe une relation empirique linéaire entre le contenu en eau liquide et le coefficient d’extinction optique pour une longueur d’onde de 11 μm. J’ai confirmé l’existence de cette relation sur la base d’observations récentes plus précises que celle des années 70, et ai déterminé ses limites de validité. Les brouillards se développent du sol jusqu’à quelques centaines de mètres, c’est donc sur cette gamme d’altitude que nous devons pouvoir faire la mesure. J’ai analysé les choix de conception offerts par les lidars afin de déterminer le système le plus performant pour notre application. Tout d’abord, j’ai analysé les capacités de mesure des lidars à détection directe et hétérodyne et j’ai mis en évidence que la détection hétérodyne est la plus appropriée. J’ai ensuite comparé les performances des configurations monostatique, bistatique et bistatique désaxé, et j’ai trouvé que la configuration monostatique est la plus appropriée. J’ai ensuite codé un simulateur instrumental et mis en évidence un biais de mesure lors de la restitution du coefficient d’extinction sur les premières centaines de mètres. J’ai proposé et validé une correction de ce biais. J’ai ensuite établi deux approximations analytiques pour le biais et l’écart-type de l’estimateur du coefficient d’extinction. Avec le simulateur, elles ont permis de se faire une idée de la portée et de la précision qui pourront être obtenues. / The objective of the present study is the design of a lidar for the measurement of vertical profiles of liquid water content in fogs. Presently, there is no system able to measure such profile. The liquid water content is measured at ground or at limited number of altitudes. Yet, the information would improve our understanding of fog processes and provide valuable data for controlling fog forecast models. Its feasibility is theoretically possible because it was shown in the late 70s that the liquid water content and the optical extinction at 11μm are empirically linked by a linear relationship. My first objective was to test this relationship with rencent observations more precise than in the late 70s. The relationship is confirmed within limits that I tried to determine. The vertical extension of fogs is several hundreds of meters. We thus need a lidar with a maximum range of several meters. I compared the range of a direct versus a heterodyne lidar and I found the heterodyne lidar is more appropriate. I have developed analytic approximations of the heterodyne efficiency for several transmitter configurations - monostatic, bistatic with parallel or non-parallel axes - and found the monostatic configuration gives the best results at short range. I coded a simulator for the lidar and showed the retrieval of the extinction coefficient from lidar signals with the usual signal processing technique produces biases at short range. I proposed and validated a correction scheme. I derived two analytic approximations for the bias and the standard deviation of the estimations of the extinction coefficient. They were used to estimate the practical range and accuracy a lidar can achieve for the measurement of the liquid water content in fogs.

Trick of the Light is an experiment in strategic game design based on imperfect information in a unique fog of war setting. A hybrid of real-time-strategy, role-playing-game and roguelike genres, the game challenges players to maintain an expansive base system without being able to see anything beyond their own limited vision radius. All units, allied or enemy, maintain private memories about what they have seen, and must directly exchange information to keep up to date. The player acts as commander, making decisions and giving orders while dealing with adversaries, sabotage and misinformation. Testing was done to see if the new concepts could be understood in-game and garner any interest for further development, which proved to be positive in both cases despite complaints related to having less direct control over allies.

In this thesis, we investigate the double-pumped L-band (1570-1610 nm) amplified spontaneous emission (ASE) fiber source by employing the 1480 nm bi-directional pumping configuration. First, we chose the adequate fiber length, and then adjusted the pump power to optimize the characteristics of the ASE source in different reflectance. The characteristics are experimentally examined and compared in terms of output power, mean wavelength, linewidth, flatness and conversion efficiency in three configurations with forward-forward (FF), forward-backward (FB) and backward-forward (BF) structures. In our experiments, FB configuration with EDF length of 93 m and reflectance of 30 ¢H is the best one to be an L-band ASE fiber source with an output power(POUT) of 71.8 mW, a mean wavelength(£fm) of 1584.3 nm, a linewidth(£G£f) of 41.6 nm, the flatness(£GP) of 1 dB, and the pump conversion efficiency(£b) of 42.2 ¢H.

Mémoire (M.Sc.A.) -- Université du Québec à Chicoutimi, 1987. / Document électronique également accessible en format PDF. CaQCU

Thesis (M.S.)--Naval Postgraduate School, 1976. / Includes bibliographical references (leaves 141-142).

Thesis (M.S.)--Naval Postgraduate School, 1981. / Includes bibliographical references (leaves 124-126).