scholarly journals A High-resolution Aerial System of a New Type

1953 ◽  
Vol 6 (3) ◽  
pp. 272 ◽  
Author(s):  
BY Mills ◽  
AG Little

A method of constructing an aerial system of high resolution but small area and low cost is described. Its application to the production of narrow pencil beams at metre wavelengths for investigations in radio astronomy is discussed. A small-scale model has been constructed to test the principle.

1984 ◽  
Vol 21 (2) ◽  
pp. 371-375 ◽  
Author(s):  
D. H. Shields ◽  
L. Domaschuk ◽  
D. W. Corkal ◽  
J. R. McCutchon

A new way to construct artificial islands of sand is described. The method shows promise of considerable cost saving. The present high cost of island building is due to the difficulty of making underwater sand slopes steep. Simply dumping sand into the ocean results in slopes of from 12 to 15 horizontal to 1 vertical. These shallow slopes have enormous implications in terms of sand volume and cost. The sand can be tremied into place to form a steep-sided ring or bund. Handling large quantities of sand in this way is expensive. Small-scale model tests show that if the sand is mixed with certain chemicals the resulting 'cohesion' enables the sand to fall through seawater as a block, with little dispersion. Steep underwater slopes result. Low-cost, nontoxic (environmentally safe) chemicals were used in the experiment. Keywords: construction, artificial islands, sand, oceans, dredging.


Author(s):  
M. C. Gosling

This paper describes the design, construction and development of a rig that allows small scale model turbines to be tested at near ambient conditions and low power levels. The objective being to obtain reliable performance data quickly and at low cost. The testing of a model turbine, installed in this rig, is described and design details of the turbine are included.


1971 ◽  
Vol 50 (3) ◽  
pp. 535-543 ◽  
Author(s):  
Garrett M. Odell ◽  
Leslie S. G. Kovasznay

The novel idea is to use a disk pump to drive each fluid layer independently round a closed-return density-stratified water channel. A small-scale model was built and tested to demonstrate the feasibility of the idea. A hydrogen-bubble technique was used for both flow visualization and velocity measurement. Density measurements were made with an electrical conductivity probe developed by the authors. The tests have demonstrated the usefulness of such a facility, especially for long steady-state experiments in density-stratified flows.


Author(s):  
Segen F. Estefen ◽  
Paulo Roberto da Costa ◽  
Eliab Ricarte ◽  
Marcelo M. Pinheiro

Wave energy is a renewable and non-polluting source and its use is being studied in different countries. The paper presents an overview on the harnessing of energy from waves and the activities associated with setting up a plant for extracting energy from waves in Port of Pecem, on the coast of Ceara State, Brazil. The technology employed is based on storing water under pressure in a hyperbaric chamber, from which a controlled jet of water drives a standard turbine. The wave resource at the proposed location is presented in terms of statistics data obtained from previous monitoring. The device components are described and small scale model tested under regular waves representatives of the installation region. Based on the experimental results values of prescribed pressures are identified in order to optimize the power generation.


2011 ◽  
Vol 25 (4) ◽  
pp. 1485-1496 ◽  
Author(s):  
Min Kuang ◽  
Zhengqi Li ◽  
Pengfei Yang ◽  
Jinzhao Jia ◽  
Qunyi Zhu

Survey Review ◽  
2014 ◽  
Vol 46 (339) ◽  
pp. 417-425 ◽  
Author(s):  
H-M. Chen ◽  
M. Smith ◽  
H-S. Yu ◽  
N. Kokkas

1989 ◽  
Vol 10 (4) ◽  
pp. 279-286 ◽  
Author(s):  
Peter Feldman ◽  
Lowell Winkelman ◽  
Helen Evans ◽  
Martin Pinnell ◽  
Fiona Murdoch ◽  
...  

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