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The measured brightness temperature is a good approximation to the brightness temperature at the center of the lunar disk because of the narrow antenna beam and because the temperature distribution over the central portion of the moon's disk is nearly uniform.
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measured and brightness
Not all the observers have used the same procedures or made the same assumptions about the lunar brightness distribution when reducing the data, and this, together with differences in the methods of calibrating the antennae and receivers, must account for much of the disagreement in the measured radio brightness temperatures.
The ratio of the measured antenna temperature change during a drift scan across the moon to the average brightness temperature of the moon over the antenna beam ( assuming that the brightness temperature of the sky is negligible ) was found, by graphical integration of the antenna directivity diagram, to be 0.85.
Absolute magnitude ( also known as absolute visual magnitude when measured in the standard V photometric band ) is the measure of a celestial object's intrinsic brightness.
Paper brightness is typically measured at 457 nm, well within the fluorescent activity range of brighteners.
The brightness of a star, as seen from Earth, is measured with a standardized, logarithmic scale.
In the 1980s, astronomers realized that the combination of CCD imagers and computers would allow the brightness of millions of stars to be measured each night.
An EL film is a so-called Lambertian radiator: unlike with neon lamps, filament lamps, or LEDs, the brightness of the surface appears the same from all angles of view ; electroluminescent light is not directional and therefore hard to compare with ( thermal ) light sources measured in lumens or lux.
; Wider viewing angles & improved brightness: OLEDs can enable a greater artificial contrast ratio ( both dynamic range and static, measured in purely dark conditions ) and viewing angle compared to LCDs because OLED pixels directly emit light.
* That in 1612 he measured the diameter of the Andromeda nebula and discerned it as having a dull, pale light which increased in brightness toward its center, like " a candle shining through horn ".
For this purpose he employed an instrument known as the " wedge photometer ", with which he measured the relative brightness of 2, 784 stars between the North Pole and about-10 ° declination.
* Magnitude of brightness or intensity of a star or an earthquake as measured on a logarithmic scale
The eye senses brightness approximately logarithmically over a moderate range ( but more like a power law over a wider range ), and stellar magnitude is measured on a logarithmic scale.
Although it seems that the sun is the brightest spot on the canvas, it is in fact, when measured with a photometer, the same brightness ( or luminance ) as the sky.
On September 9 and 16, 1999, Charbonneau's team measured a 1. 7 % drop in HD 209458's brightness, which was attributed to the passage of the planet across the star.
The luminosity is the amount of light energy emitted by the galaxy per unit time ; it can be measured using the galaxy's apparent brightness when the distance to the galaxy is known.
The candlepower of a lamp was measured by judging by eye the relative brightness of adjacent surfaces, one illuminated only by a standard lamp ( or candle ) and the other only by the lamp under test.
Because of the demands on observing time required to obtain spectroscopic redshifts ( i. e., true redshifts measured by velocity ), it has become commonplace to use photometric redshifts, based on brightness.
LEDs are measured so that the line along half the viewing-angle from directly forward is half the brightness as at directly forward.
Note that light is also measured using the techniques of photometry, which deal with brightness as perceived by the human eye, rather than absolute power.
The figure illustrates how mass deficits are measured, using the observed brightness profile of a galaxy.
The overall brightness of an extended astronomical object such as a galaxy, star cluster, or nebula, can be measured by its total magnitude, integrated magnitude or integrated visual magnitude ; a related concept is surface brightness, which specifies the brightness of a standard-sized piece of an extended object.
measured and temperature
The mean temperature of this region was approximated by the temperature measured halfways between the edge of the hot spot and the rim of the plug.
The upstream gas temperature measured with the thermocouple shown in figure 2 was Af.
A single value of the thermal relaxation time Af at room temperature was measured by the progressive saturation method.
Variations in sound velocity should be measured rather than temperature, because more of the variables would be encompassed.
The dryer is provided with a means of maintaining a drying temperature of 120-degrees - 160-degrees-F ( 49*0 - 71*&0C. ), measured in the exhaust vent as close as possible to the drying chamber.
Any information may be conveyed by an analog signal ; often such a signal is a measured response to changes in physical phenomena, such as sound, light, temperature, position, or pressure.
The concept being measured over the circuit, whether sound, light, pressure, temperature, or an exceeded limit, remains from end to end.
Absolute, or thermodynamic, temperature is conventionally measured in kelvins ( Celsius-scaled increments ) and in the Rankine scale ( Fahrenheit-scaled increments ) with increasing rarity.
If the slowing down of certain seismic waves caused by the damp spot helped uncover the underground ocean, the unusual temperature variation with depth measured in 241 inactive oil wells helped locate the subterranean river.
A measured volume ( typically 10 – 50 μL ) or a weighed mass ( typically around 1 mg ) of a solid sample are introduced into the graphite tube and subject to a temperature program.
However, before reaching the transition temperature, the specific heat of the superconductor becomes even higher than that of the normal conductor ( measured immediately above the transition ) and the ratio of these two values is found to be universally given by 2. 5.
The quantity that is conveniently measured at constant experimentally controlled temperature, the isothermal compressibility, is defined by
Provided that the temperature is measured in the thermodynamic absolute scale, the relation is expressed in the formula
The dimension of a physical quantity is the combination of the basic physical dimensions ( usually mass, length, time, electric charge, and temperature ) which describe it ; for example, speed has the dimension length per time, and may be measured in meters per second, miles per hour, or other units.
At standard temperature, pressure and concentration conditions, the cell's emf ( measured by a multimeter ) is 0. 34 V. By definition, the electrode potential for the SHE is zero.
The fact that the Carnot function could be the temperature, measured from zero, was suggested by Joule in a letter to Kelvin, and this allowed Kelvin to establish his absolute temperature scale.
For many geologic applications, isotope ratios are measured in minerals that give the amount of time that has passed since a rock passed through its particular closure temperature, the point at which different radiometric isotopes stop diffusing into and out of the crystal lattice.
measured and is
The element is inserted in the discharge circuit in place of the exploding wire, and the calorimetric heating of the element is measured with high accuracy.
This is used as a reference for comparing the ohmic heating and the electrical energy obtained from the measured current through the element and the measured voltage across the element.
The quality of a president's leadership is measured first by his success in building up the faculty.
When tire size is measured in this manner a constant of 168 is used in the formula.
The measurements made with the NRL 50-foot reflector, which is altitude-azimuth-mounted, would have shown a systematic change with local hour angle in the measured intensities of Venus and Jupiter if a substantial part of the radiation had been linearly polarized.
The result of the observations is Af where the phase angle, Q, is measured in degrees from new moon and the probable errors include absolute as well as relative errors.
In free-burning electric arcs, for instance, approximately 90% of the total arc power is transferred to the anode giving rise to local heat fluxes in excess of Af as measured by the authors -- the exact value depending on the arc atmosphere.
Here, H is the coatings removal force measured parallel to the surface of the substrate and T is the film thickness.
The angle Af is measured in the medium of index Af.
Space in any form is completely measured by the three dimensions.
Being a dimensionless fraction, it may also be expressed as a percentage, and is measured on a scale from zero for no reflecting power of a perfectly black surface, to 1 for perfect reflection of a white surface.
The deadline for beginning an appeal can often be very short: traditionally, it is measured in days, not months.
In logic, the time that an algorithm requires to complete cannot be measured, as it is not apparently related with our customary physical dimension.
When speed is being measured, the instruction set matters.
The electron is by far the least massive of these particles at, with a negative electrical charge and a size that is too small to be measured using available techniques.
0.399 seconds.