1,143,339 research outputs found
Solar heating system
A system is disclosed for using solar energy to heat the interior of a structure. The system utilizes a low cost solar collector to heat a recirculating air mass which then flows through a series of interconnected ducts and passageways without the use of exterior fans or blowers. Heat is transferred from the air mass to the structure's interior and the air mass is then reheated
Solar tracking system
A solar tracker for a solar collector is described in detail. The collector is angularly oriented by a motor wherein the outputs of two side-by-side photodetectors are discriminated as to three ranges: a first corresponding to a low light or darkness condition; a second corresponding to light intensity lying in an intermediate range; and a third corresponding to light above an intermediate range, direct sunlight. The first output drives the motor to a selected maximum easterly angular position; the second enables the motor to be driven westerly at the Earth rotational rate; and the third output, the separate outputs of the two photodetectors, differentially controls the direction of rotation of the motor to effect actual tracking of the Sun
The formation of the solar system
The solar system started to form about 4.56 Gyr ago and despite the long
intervening time span, there still exist several clues about its formation. The
three major sources for this information are meteorites, the present solar
system structure and the planet-forming systems around young stars. In this
introduction we give an overview of the current understanding of the solar
system formation from all these different research fields. This includes the
question of the lifetime of the solar protoplanetary disc, the different stages
of planet formation, their duration, and their relative importance. We consider
whether meteorite evidence and observations of protoplanetary discs point in
the same direction. This will tell us whether our solar system had a typical
formation history or an exceptional one. There are also many indications that
the solar system formed as part of a star cluster. Here we examine the types of
cluster the Sun could have formed in, especially whether its stellar density
was at any stage high enough to influence the properties of today's solar
system. The likelihood of identifying siblings of the Sun is discussed.
Finally, the possible dynamical evolution of the solar system since its
formation and its future are considered.Comment: 36 pages, 7 figures, invited review in Physica Script
Solar energy control system
A solar energy control system for a hot air type solar energy heating system wherein thermocouples are arranged to sense the temperature of a solar collector, a space to be heated, and a top and bottom of a heat storage unit is disclosed. Pertinent thermocouples are differentially connected together, and these are employed to effect the operation of dampers, a fan, and an auxiliary heat source. In accomplishing this, the differential outputs from the thermocouples are amplified by a single amplifier by multiplexing techniques. Additionally, the amplifier is corrected as to offset by including as one multiplex channel a common reference signal
Vesta and Ceres: crossing the history of the Solar System
The evolution of the Solar System can be schematically divided into three
different phases: the Solar Nebula, the Primordial Solar System and the Modern
Solar System. These three periods were characterized by very different
conditions, both from the point of view of the physical conditions and from
that of the processes there were acting through them. Across the Solar Nebula
phase, planetesimals and planetary embryos were forming and differentiating due
to the decay of short-lived radionuclides. At the same time, giant planets
formed their cores and accreted the nebular gas to reach their present masses.
After the gas dispersal, the Primordial Solar System began its evolution. In
the inner Solar System, planetary embryos formed the terrestrial planets and,
in combination with the gravitational perturbations of the giant planets,
depleted the residual population of planetesimals. In the outer Solar System,
giant planets underwent a violent, chaotic phase of orbital rearrangement which
caused the Late Heavy Bombardment. Then the rapid and fierce evolution of the
young Solar System left place to the more regular secular evolution of the
Modern Solar System. Vesta, through its connection with HED meteorites, and
plausibly Ceres too were between the first bodies to form in the history of the
Solar System. Here we discuss the timescale of their formation and evolution
and how they would have been affected by their passage through the different
phases of the history of the Solar System, in order to draw a reference
framework to interpret the data that Dawn mission will supply on them.Comment: 27 pages, 1 figure, 2 tables; the final publication is available at
http://www.springerlink.co
Solar Furnace: Heliostat and Concentrator Design
In recent decades, solar energy has been shown as a viable, clean, and abundant alternative to fossil fuels. Many methods of solar energy collection are being researched, with solar thermal electrochemistry being one of the most promising. Solar thermal electrochemistry uses sunlight to heat a furnace to temperatures nearing 2000 K. At these temperatures, metallic oxides can be decomposed to metals and oxygen with minimal electrical work. Achieving these high temperatures requires a solar furnace that consists of a heliostat to track and reflect the sun’s rays into a concentrator, which then focuses the sunlight to a single point in a solar thermal chemical reactor. A system of louvers regulates the amount of sunlight entering the system. Our research focuses on the design and development of the solar furnace components; specifically, the design and construction of the heliostat structure, the heliostat control system, and the concentrator
The galactic environment of the Sun
The interstellar cloud surrounding the solar system regulates the galactic
environment of the Sun and constrains the physical characteristics of the
interplanetary medium. This paper compares interstellar dust grain properties
observed within the solar system with dust properties inferred from
observations of the cloud surrounding the solar system. Properties of diffuse
clouds in the solar vicinity are discussed to gain insight into the properties
of the diffuse cloud complex flowing past the Sun. Evidence is presented for
changes in the galactic environment of the Sun within the next 10--10
years. The combined history of changes in the interstellar environment of the
Sun, and solar activity cycles, will be recorded in the variability of the
ratio of large- to medium-sized interstellar dust grains deposited onto
geologically inert surfaces. Combining data from lunar core samples in the
inner and outer solar system will assist in disentangling these two effects.Comment: 30 pages, 2 figures, JGR-Space Physics, in pres
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