Solar pumped laser

A solar pumped laser is described in which the lasant is a gas that will photodissociate and lase when subjected to sunrays. Sunrays are collected and directed onto the gas lasant to cause it to lase. Applications to laser propulsion and laser power transmission are discussed

Ventilation of the North Atlantic Ocean during the Last Glacial Maximum: A comparison between simulated and observed radiocarbon ages

The distribution of radiocarbon during simulations of the Last Glacial Maximum with a coupled ocean-atmosphere-sea ice model is compared with sediment core measurements from the equatorial Atlantic Ceara Rise, Blake Ridge, Caribbean Sea, and South China Sea. During these simulations we introduce a perturbation of North Atlantic freshwater fluxes leading to varying strengths of the Atlantic meridional overturning. The best fit with the observations is obtained for an overturning weakened by 40% compared with today. Further, we simulate the phenomenon of an “age reversal” found in deep sea corals, but we suggest that this indicates rather a sudden interruption of deep water formation instead of an increase in ventilation, which was suggested earlier

A preliminary training guide for utilizing high-altitude, color-infrared photography in compiling soil maps

Instruction for acquiring and analytically processing small-scale color-infrared photography to perform a soil resources inventory over forests of the southern U.S. is provided. Planning the project; acquiring aerial photography, materials, equipment and supplemental data; and preparing the photography for analysis are discussed. The procedures for preparing ancillary and primary component overlays are discussed. The use of correlation charts and dichotomous keys for mountain landforms, water regime, and vegetation is explained

POTENTIAL WATER USE CONFLICTS GENERATED BY IRRIGATED AGRICULTURE IN RHODE ISLAND

This study constructs a simulation model to evaluate the potential for conflict among residential and agricultural users of water in southern Rhode Island. The model estimates the profitability of irrigation and turf farms and projects the total use and the economic value of irrigation water. The results indicate that the economic value of irrigation water compares favorably with current residential water prices in the area. In addition, substantial demand for irrigation water is projected. Given current rates of growth in turf acreage and residential water use, there appears to be a significant potential for conflict, particularly given the absence of well developed institutions for allocating water among users.Resource /Energy Economics and Policy,

High-Q nested resonator in an actively stabilized optomechanical cavity

Experiments involving micro- and nanomechanical resonators need to be carefully designed to reduce mechanical environmental noise. A small scale on-chip approach is to add an additional resonator to the system as a mechanical low-pass filter. Unfortunately, the inherent low frequency of the low-pass filter causes the system to be easily excited mechanically. Fixating the additional resonator ensures that the resonator itself can not be excited by the environment. This, however, negates the purpose of the low-pass filter. We solve this apparent paradox by applying active feedback to the resonator, thereby minimizing the motion with respect the front mirror of an optomechanical cavity. Not only does this method actively stabilize the cavity length, but it also retains the on-chip vibration isolation.Comment: Minor adjustments mad

CONTINGENT VALUATION FOCUS GROUPS: INSIGHTS FROM ETHNOGRAPHIC INTERVIEW TECHNIQUES

Despite the many important uses (and potential abuses) of focus groups in survey design, the CV literature presents few guidelines to aid moderators in their interaction with focus group participants. This paper draws on the theory and practice of ethnographic interviewing to introduce general guidelines that can improve focus groups as an aid to CV research. The proposed guidelines illustrate types of questions that should reduce speculation and moderator-introduced bias in focus group responses, and improve the correspondence between focus group responses and actual behavior. The paper illustrates these ethnographic guidelines through a CV application concerning watershed resources.Research Methods/ Statistical Methods,

Effects of the Great Drought on the Prairies of Iowa, Nebraska, and Kansas

The response of prairie vegetation of eastern Nebraska during the great drought of 1934 has been described (Weaver, Stoddart, and Noll, \u2735). The purpose of the present study was to determine the results of the drought during the following year. The work has been extended to include the mixed prairie of west central Kansas

Defoliation responses of different grapevine cultivars to postharvest ethephon treatments

The defoliation responses of several grapevine cultivars to postharvest ethephon sprays at 0, 500, 2000, 5000 ppm were observed. Sprays were applied at the beginning of October to vines of Barbera, Carignane, Emerald Seedless, Ribier, Ruby Seedless, Thompson Seedless and Flame Tokay cultivars.The most effective concentration was 5000 ppm. The defoliation response varied greatly among the varieties. Barbera and Carignane were almost completely defoliated 20-30 d after treatment, whereas Flame Tokay showed no response. However, high concentrations of ethephon resulted in a considerable delay in shoot development the following spring.Défoliation induite en différents cépages par un traitement avec de l'éthéphon après la vendangeLa défoliation causée par des traitements d'éthephon (0, 500, 2000, 5000 ppm) a été étudiée sur différents cépages (V. vinifera).Les applications ont été faites le 10 octobre sur les cépages à raisin de table et de cuve ci-après: Barbera, Carignane; Emerald Seedless, Ribier, Ruby Seedless, Thompson Seedless et Flame Tokay. La concentration de 5000 ppm se révéla la plus efficace. La défoliation des plantes traitées a été très différente selon les cépages: Barbera et Carignane par exemple ont été presque complètement privés des feuilles après 20-30 d du traitement, tandis que le Flame Tokay ne donna qu'une très faible réponse.Il faut signaler en tout cas que les concentrations les plus fortes d'éthéphon ont causé un retard considerable dans le débourrement du printemps suivant

Energy Spectrum Evolution of a Diffuse Field in Elastic Body Caused by Weak Nonlinearity

We study the evolution of diffuse elastodynamic spectral energy density under the influence of weak nonlinearity. It is shown that the rate of change of this quantity is given by a convolution of the linear energy at two frequencies. Quantitative estimates are given for sample aluminum and fused silica blocks of experimental interest.Comment: 9 pages, 3 figures; revised for better presentatio