Compact Fluorescent Lamps In Focus

Energy savings

CFLs use 70 to 80 percent less energy than incandescent bulbs. The typical incandescent lamp wastes 90 percent of the energy it uses since it produces heat rather than light. A 100-watt incandescent lamp may be replaced with a 20 to 23-watt CFL. Although CFLs may appear different than the common incandescent bulbs, CFLs fit most standard fixtures found in homes today. The screw-in base is the same for both lamps.

Long Life

CFLs last approximately 6,000 tto 10,000 hours. This is 8 to 13 times longer than the life of an incandescent lamp with an expected life of 750 to 1,000 hours.

Warm Light

Most CFLs have improved color rendition. The light is of a warm tone that is almost identical to that of an incandescent lamp. Most people can't tell the difference.


Savings chart - Quality CFL vs. quality incandescent bulb




Taken from The Philippine Star

Calorimetry

the discovery of certain thermal properties of substances such as calorific value, specific heat or latent heat in physics and chemistry. The instrument used is called a calorimeter and it consists essentially of apparatus which allows the substance to be burnt and the heat transferred to a surrounding body of water, enabling the rise in temperature and therefore the heat output to be measured.

Taken from Dictionary of Science

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Calorimetry is the science of measuring the heat of chemical reactions or physical changes. Calorimetry involves the use of a calorimeter. The word calorimetry is derived from the Latin word calor, meaning heat. Scottish physician and scientist Joseph Black, who was the first to recognize the distinction between heat and temperature, is said to be the founder of calorimetry.

Indirect calorimetry calculates heat that living organisms produce from their production of carbon dioxide and nitrogen waste (frequently ammonia in aquatic organisms, or urea in terrestrial ones), OR from their consumption of oxygen. Lavoisier noted in 1780 that heat production can be predicted from oxygen consumption this way, using multiple regression. The Dynamic Energy Budget theory explains why this procedure is correct. Of course, heat generated by living organisms may also be measured by direct calorimetry, in which the entire organism is placed inside the calorimeter for the measurement.

The specific heat formula is as follows:

where

q is energy, or heat,

m is mass,

c is specific heat capacity,

ΔT is change in temperature.

Taken from Wikipedia

Joule

the unit for all ENERGY measurements. It is the mechanical equivalent of heat, and one joule (J) is equal to a force of one NEWTON moving one metre, i.e. 1J = 1Nm. It is named after James Prescott Joule (1818-1889), a British physicist who investigated the relationship between mechanical, electrical and heat energy, and, from such investigations, proposed the first law of THERMODYNAMICS, the conservation of energy.

Taken from Dictionary of Science

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The joule (symbol J), named for James Prescott Joule, is the derived unit of energy in the International System of Units. It is the energy exerted by the force of one newton acting to move an object through a distance of one metre. In terms of dimensions:

One joule is defined as the amount of work done by a force of one newton moving an object through a distance of one metre. Other relationships are:

• The work required to move an electric charge of one coulomb through an electrical potential difference of one volt; or one coulomb volt (C·V). This relationship can be used to define the volt;

• The work required to continuously produce one watt of power for one second; or one watt second (W·s) (compare kilowatt hour). This relationship can be used to define the watt.

Taken from Wikipedia

Calorie

a unit of quantity of heat defined as that heat needed to raise the temperature of one gram of water through 1°C. Nowadays, it has largely been replaced by the JOULE (1 calorie = 4.186 joules).

Taken from Dictionary of Science

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The calorie is a pre-SI metric unit of energy. The unit was first defined by Professor Nicolas Clément in 1824 as a unit of heat. This definition entered French and English dictionaries between 1841 and 1867. In most fields its use is archaic, having been replaced by the SI unit of energy, the joule. However, in many countries it remains in common use as a unit of food energy. The kilocalorie per mole remains in use in computational chemistry and molecular spectroscopy.

Definitions vary but are all based on the specific heat capacity of water. The gram calorie, approximately 4.2 J, is based on one gram of water. The kilogram calorie, equal to one thousand gram calories, is based on one kilogram of water. In the context of nutrition, and especially food labelling, a larger unit is used and referred to interchangeably by the terms calorie (or Calorie) and kilocalorie.

Taken from Wikipedia

Absolute Zero

the temperature at which the particles that make up matter have no energy at all whether due to heat or motion. It is theoretically given the value of -273.15°Celsius (-459.67° Fahrenheit).

Taken from Dictionary of Science
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Absolute zero is the temperature at which entropy reaches its minimum value. As implied by the laws of thermodynamics, absolute zero cannot be reached by artificial or natural means because this would require a system to be fully removed from the rest of the universe. A system at theoretical absolute zero possesses quantum mechanical zero-point energy. While all molecular motion does not cease at absolute zero, the system does not have enough energy for transference to other systems. It is therefore correct to say that molecular energy is minimal at absolute zero.

By international agreement, absolute zero is defined as precisely 0 K on the Kelvin scale and as −273.15° on the Celsius scale. Absolute zero is also precisely equivalent to 0 R on the Rankine scale (same as Kelvin but measured in Fahrenheit intervals) and −459.67° on the Fahrenheit scale. Though it is not theoretically possible to cool any substance to 0 K, scientists have made great advancements in achieving temperatures close to absolute zero, where matter exhibits quantum effects such as superconductivity and superfluidity.

For the kinematics of molecules at absolute zero on a larger scale, which is easier to understand, see kinetic energy.

Taken from Wikipedia