Valve

in biology a piece of tissue attached to the wall of a tube that ensures the flow of blood is in one direction. The most important valves are the ones found in the HEART and VEINS, which prevent a backflow of blood. In engineering, valves are used in a similar way, to control the flow of fluids through pipes.

Taken from Dictionary of Science

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A valve is a device that regulates the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category. In an open valve, fluid flows in a direction from higher pressure to lower pressure.

Valves are also found in the human body. For example, there are several heart valves which control the flow of blood in the chambers of the heart and maintain the correct pumping action.

Valves are used in a variety of contexts, including industrial, military, commercial, residential, and transportation.

The industries in which the majority of valves are used are oil and gas, power generation, mining, water reticulation, sewerage and chemical manufacturing.

Plumbing valves, such as taps for hot and cold tap water are the most noticeable types of valves. Other valves encountered on a daily basis include gas control valves on cookers, small valves fitted to washing machines and dishwashers, and safety devices fitted to hot water systems.

Valves may be operated manually, either by a hand wheel, lever or pedal. Valves may also be automatic, driven by changes in pressure, temperature, or flow. These changes may act upon a diaphragm or a piston which in turn activates the valve, examples of this type of valve found commonly are safety valves fitted to hot water systems or boilers.

More complex control systems using valves requiring automatic control based on an external input (i.e., regulating flow through a pipe to a changing set point) require an actuator. An actuator will stroke the valve depending on its input and set-up, allowing the valve to be positioned accurately, and allowing control over a variety of requirements.

Valves are also found in the Otto cycle (internal combustion) engines driven by a camshaft, tappets or push rods where they play a major role in engine cycle control.

Taken from Wikipedia

Quartz

one of the most common rock-forming minerals, SiO₂, which is found in many different kinds of rock. It also forms some semi-precious stones, e.g. amethyst and agate.

Taken from Dictionary of Science

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Quartz is the second most abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO₄ silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO₂.

There are many different varieties of quartz, several of which are semi-precious gemstones. Especially in Europe and the Middle East, varieties of quartz have been since antiquity the most commonly used minerals in the making of jewelry and hardstone carvings.

Taken from Wikipedia

Haemoglobin

an iron-containing red pigment, which is found within the red blood cells (called ERYTHROCYTES) of vertebrates and which is responsible for the transport of oxygen around the body. In actively metabolizing tissue such as the muscles, haemoglobin exchanges oxygen for carbon dioxide (CO₂), which is then carried in the blood back to the heart and pumped to the lungs, where the haemoglobin loses the CO₂ and regains oxygen.

Taken from Dictionary of Science

Water

hydrogen oxide (H20), a compound that is found everywhere. It can occur as solid, liquid and gas phases. It forms a very large part of the Earth's surface and is vital to life. It occurs in all living organisms and has a remarkable combination of properties in its solvent capacity, chemical stability, thermal properties and abundance.

Taken from Dictionary of Science

Palaeontology

is the scientific study of FOSSILS which allows information to be collected on how organisms lived, what they looked like and how they evolved with time. Fossils are found in sedimentary rocks and occur throughout most of the geological record.

Taken from Dictionary of Science

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Paleontology (British: palaeontology) is the study of prehistoric life, including organisms' evolution and interactions with each other and their environments (their paleoecology). As a "historical science" it tries to explain causes rather than conduct experiments to observe effects. Paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuvier's work on comparative anatomy, and developed rapidly in the 19th century. Fossils found in China since the 1990s have provided new information about the earliest evolution of animals, early fish, dinosaurs and the evolution of birds and mammals. Paleontology lies on the border between biology and geology, and shares with archaeology a border that is difficult to define. It now uses techniques drawn from a wide range of sciences, including biochemistry, mathematics and engineering. As knowledge has increased, paleontology has developed specialized subdivisions, some of which focus on different types of fossil organisms while others study ecological and environmental history, such as ancient climates.

Body fossils and trace fossils are the principal types of evidence about ancient life, and geochemical evidence has helped to decipher the evolution of life before there were organisms large enough to leave fossils. Estimating the dates of these remains is essential but difficult: sometimes adjacent rock layers allow radiometric dating, which provides absolute dates that are accurate to within 0.5%, but more often paleontologists have to rely on relative dating by solving the "jigsaw puzzles" of biostratigraphy. Classifying ancient organisms is also difficult, as many do not fit well into the Linnean taxonomy that is commonly used for classifying living organisms, and paleontologists more often use cladistics to draw up evolutionary "family trees". The final quarter of the 20th century saw the development of molecular phylogenetics, which investigates how closely organisms are related by measuring how similar the DNA is in their genomes. Molecular phylogenetics has also been used to estimate the dates when species diverged, but there is controversy about the reliability of the molecular clock on which such estimates depend.

Taken from Wikipedia

Calcium

a metallic substance with the symbol Ca which is common in nature being found in both plants and animals. It is essential for the normal growth and development of animals, being found in bones, teeth, blood and nerves.

Taken from Dictionary of Science

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Calcium (pronounced /ˈkælsiəm/, KAL-see-əm) is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth most abundant element by mass in the Earth's crust. Calcium is also the fifth most abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate.

Calcium is essential for living organisms, particularly in cell physiology, where movement of the calcium ion Ca²⁺ into and out of the cytoplasm functions as a signal for many cellular processes. As a major material used in mineralization of bones and shells, calcium is the most abundant metal by mass in many animals.

Taken from Wikipedia

Caffeine

a naturally-occurring chemical substance that is found in tea leaves, coffee beans and other plants. It acts as a weak stimulant on the central nervous system so after drinking a cup of coffee or tea, a person may feel more alert.

Taken from Dictionary of Science

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Caffeine is a bitter, white crystalline xanthine alkaloid that is a psychoactive stimulant drug. Caffeine was discovered by a German chemist, Friedrich Ferdinand Runge, in 1819. He coined the term kaffein, a chemical compound in coffee, which in English became caffeine.

Taken from Wikipedia

New Divide

Linkin Park

I remembered black skies, the lightning all around me

I remembered each flash as time began to blur

Like a startling sign that fate had finally found me

And your voice was all I heard that I get what I deserve

Chorus:

So give me reason to prove me wrong, to wash this memory clean

Let the floods cross the distance in your eyes

Give me reason to fill this hole, connect the space between

Let it be enough to reach the truth that lies across this new divide

There was nothing in sight but memories left abandoned

There was nowhere to hide, the ashes fell like snow

And the ground caved in between where we were standing

And your voice was all I heard that I get what I deserve

So give me reason to prove me wrong, to wash this memory clean

Let the floods cross the distance in your eyes across this new divide

Bridge:

In every loss, in every lie, in every truth that you'd deny

And each regret and each goodbye was a mistake too great to hide

And your voice was all I heard that I get what I deserve

So give me reason to prove me wrong, to wash this memory clean

Let the floods cross the distance in your eyes

Give me reason to fill this hole, connect the space between

Let it be enough to reach the truth that lies across this new divide

Across this new divide, across this new divide