Showing papers on "Solar energy published in 1971"

Pavement temperatures in the southwest

Abstract: A STUDY WAS CONDUCTED ON A TEST SECTION OF ASPHALT PAVEMENT TO PRODUCE NEEDED TEMPERATURE DATA FROM THE DESERT PORTION OF THE SOUTHWEST. SOLAR RADIATION DATA WERE RECORDED CONCURRENTLY FOR COMPARISON WITH THE TEMPERATURE DATA. TYPICAL TEMPERATURE PATTERNS FOR EACH MONTH OF THE TEST PERIOD ARE PRESENTED AND EXPLAINED WITH THE AID OF HEAT TRANSFER THEORY. PRESENTATIONS OF THE DATA SHOW THE AVERAGE MINIMUM AND MAXIMUM TEMPERATURES THROUGHOUT THE TEST PERIOD AS WELL AS THE TEMPERATURE DURATION AT VARIOUS LEVELS. EVALUATION OF THE STATISTICS HAS LED THE AUTHORS TO SUGGEST POSSIBLE ADDITIONS TO THE PRESENT METHODS OF TESTING ASPHALTIC CONCRETE FOR USE IN DESERT AREAS. COMPARISON BETWEEN SOLAR RADIATION AND TEMPERATURE SUBSTANTIATES THE THEORY THAT SHALLOW DEPTHS ARE GREATLY INFLUENCED BY THE SUN'S ENERGY. ANALYSIS OF THE DATA SHOWS THAT PREDICTION OF PAVEMENT TEMPERATURES IS POSSIBLE WITH THE USE OF INFORMATION FROM WEATHER REPORTS OF AIR TEMPERATURE AND SOLAR RADIATION. /AUTHOR/

The solar envelope

Abstract: Processes which occur within the region between approximately 2 solar radii and 25 solar radii, which is called the solar envelope and the effect on the solar wind as seen at 1 AU are discussed. In the envelope the wind speed becomes supersonic and super-Alfvenic, the magnetic energy density is larger than the flow energy density, and the magnetic energy density is much larger than the thermal energy density. Large azimuthal gradients in the bulk speed are expected in the envelope, but the stream interactions near the outer edge of the envelope are probably relatively small. Cosmic ray observations suggest the presence of hydromagnetic waves in the envelope. The collisionless damping of such waves could heat protons out to approximately 25 solar radii and thereby cause an increase in V and T sub p consistent with the observed T sub p -V relation. A mechanism which couples protons and electrons would also heat and accelerate the wind. Alfven waves can accelerate the wind in the envelope without necessarily causing heating of protons; the Lorentz force might have a similar effect.

Self-storing solar heater

Abstract: A SELF-STORING SOLAR HEATER IS DISCLOSED INSTALLED ON A HOUSE TRAILER WITH THE HEATER BEING EXTENDABLE OVER A PORTION OF THE ROOF OF THE TRAILER TO RECEIVE THE RAYS OF THE SUN DURING THE DAY AND IS STORED IN A HEATED COMPARTMENT ON COLD DAYS AND NIGHTS TO PREVENT THE WATER IN THE SOLAR HEATER FROM FREEZING. A THEREMOSTATICALLY CONTROLLED MOTOR DRIVEN REEL RETRACTS THE SOLAR HEATER INTO THE HEATED STORAGE COMPARTMENT AND A PULLEY SYSTEM ACTUATED BY THE SAME MOTOR EXTENDS THE SOLAR HEATER WHEN HEATING RAYS ARE AVAILABLE FROM THE SUN. D R A W I N G

Potential solar radiation climates of man

Abstract: A deterministic system of models relates man and other vertical objects to horizontal shortwave radiation under cloudless conditions, and permits comparison of actual conditions with an ideal standard. This is the first in a system of increasingly more complex models which will eventually solve the entire energy balance equation in bioclimatology. The parameters examined are concerned with direct solar radiation, diffuse sky radiation, diffuse radiation reflected from the ground, and the total solar heat load on man. Each latitude and each season has its own characteristic pattern of these components, which often differ drastically from data applicable to horizontal surfaces. Depending on the season, direct solar radiation on vertical objects poleward of latitude 30/sup 0/ can exceed several times the amounts incident on an equivalent horizontal surface. Direct solar radiation on vertical objects equatorward of latitude 30/sup 0/ is less than that incident on the horizontal interface.

Solar distillation apparatus

Abstract: A solar distillation apparatus for converting sea water into fresh water. A transparent dome condenses solar energy and heats sea water in a container beneath it. The periphery of the dome is provided with a continuous channel for conveying vaporized liquid into a condenser tank. Means are included for collecting rain water. A sea water supply tank is provided with a demand valve for feeding to a main heating chamber. The distilland is filtered and fed to an underground reservoir.

Is it Time for a New Look at Solar Energy

Abstract: The authors propose a solar power generating system which would produce 1,000 megawatts of electricity by the thermal conversion of sunshine to produce steam. They suggest the conversion can be done by the optical concentration of sunshine in ground collectors spread over desert regions. The collection of enough solar energy for a 1,000 megawatt generating system would require a solar power “farm” covering an area 3.8 kilometers on a side. Aden B. Meinel is director of the Optical Sciences Center, University of Arizona, his wife, Marjorie Pettit Meinel, has collaborated with him in this study.

Guidance and Navigation for Solar Electric Interplanetary Missions

Abstract: Algorithm for trajectory analysis in closed loop terminal guidance of solar electrically thrusted interplanetary spacecraft

Thermal emissivity and solar absorptivity of aluminum coated with double layers of aluminum oxide and silicon oxide.

Abstract: Thermal emissivity and solar absorptivity of Al coated with surface layers of aluminum oxide and silicon oxide, describing fabrication techniques and performance measurements

Variation of solar attenuation with height over an urbanized area

Abstract: The information presented in this paper is directed to environmental scientists who are concerned about the quality of air over an urban area. Specifically, the purpose of this study is to show quantitatively the magnitude of solar attenuation for individual air layers in the lowest 1000 m of an urban atmosphere. This reveals dramatically the diverse variation of mass concentration with height. The information is useful in urban planning, in site selection, and in air quality control. The data were gathered on different roof top levels and on helicopter flights using modified Volz sun photometers, psychrometers, hot-wire anemometers, and an electric thermometer. The results show that, for instance, on a "polluted" day the lowest 1000 m of air attenuate about 65% of the solar beam, whereas on a “clean” day the contribution to the total solar attenuation is still 30%. Shallow air layer increments of 45 m near the ground were found to contribute up to 21% to the total solar attenuation. Aerosols form the dom...

Silicon Solar Cells at Low Temperature

Abstract: Electrical characteristics of n-p silicon solar cells have been obtained experimentally over the temperature range of +28 to ?175° and for illumination intensities from 140 to 1.5 mW/cm2. Critical parameters and their distribution are presented for several hundred solar cells from various manufacturers. The effect of cell selection either to a minimum power output at 28° at 5 mW/cm2 or to a minimum open-circuit voltage at ?128° at 5.16 mW/cm2 upon the magnitude and distribution of the critical parameters is investigated. Considerable differences are noted, not just between cells, but also between lots from various manufacturers. Correlation analysis reveals no parameter which when measured at room temperature will predict the power output at low temperatures. This is due to a number of anomalies of the output characteristics at low temperature. These are a lack of the open voltage to continue to increase with decreasing temperature and a double break in the current-voltage characteristics. In addition, some cells show low shunt resistance which makes them have a poor performance at low intensities.