Prevention in Automobiles

If you are dealing with equipment powered by liquid hydrogen, you must keep it from being ignited. You must eliminate all sources of sparks. This could come from electrical equipments, static electricity, fire, and hot objects. All safety measures should take place not only at your place, but also in fueling stations, and automobile manufacturing industries.

Liquid Hydrogen Uses

Liquid hydrogen is the liquid state of the gaseous element hydrogen. Its chemical symbol is LH2, the "L" standing for liquid. It is made and kept at exceptionally cold temperatures, and reaches its liquefied state at -423.17 degrees Fahrenheit. It is known as cryogenic liquid and has many uses, mainly in scientific fields of study.

History

Liquid hydrogen has been known and studied since the 19th century, when the Scottish chemist, James Dewar, first liquefied it. Previously, he invented a vacuum flask that enabled him to liquefy hydrogen by using a regenerative cooling system. The system cooled the gas by allowing it to expand and then pass through a heat exchanger that had in it more compressed gas. Paul Harteck and Karl Bonhoeffer expanded on Dewar’s knowledge and created parahydrogen in 1929. Parahydrogen is hydrogen that has protons aligned on poles opposite to each other.

Rocket Engines

Liquid hydrogen is most commonly known as a component of rocket engine combustibility. The presence of liquid hydrogen cools the nozzle and other elements of the combustion chamber that will be exposed to extreme heat. Upon becoming gaseous and mixing with an oxidizer such as liquid oxygen, the liquid hydrogen ignites and creates a powerful thrust that will enable large projectiles to leave Earth’s gravity. The great clouds of "smoke" that you see upon the launch of the space shuttle are actually liquid hydrogen returning to its natural state, boiling away into the atmosphere. NASA is the largest consumer of liquid hydrogen in the world.

Fuel Cells

Liquid hydrogen, in fuel cells, powers hydrogen cars and buses. Buses that use liquid hydrogen have longer fuel ranges and capabilities than regular combustion engine vehicles that use petroleum products, according to Hydrogen Fuel Cars Now. The German car manufacturer BMW already has a hydrogen mini car that runs on a 12-cylinder engine. Hydrogen is absorbed back into the atmosphere, making it an alternative green fuel source.

Magnets

Liquid hydrogen helps cool superconductive magnets used in capturing scientific images, including the magnets that create images of the body that are captured by the MRI, or Magnetic Resonance Imaging. Liquid hydrogen is applied to magnets that would otherwise break with the amount of heat they generate in creating magnetic fields. These magnetic fields affect the hydrogen in the water contained in the body, and these will align with the magnetic field to help capture an image. Such magnetic fields are used in the study of extremely small subatomic particles and are of practical use in physics laboratories around the world.

Electromagnetic Energy Power Sources

Electricity is the flow of electrons. For more than a century we have been finding interesting ways to use electrical energy. An electromagnetic power source must either store a surplus of electrons or be able to use some force - usually magnetism - to force electrons to move back and forth in wavelike motions. Electromagnetic energy usually refers to systems that transfer electrical power wirelessly. Electromagnetic energy power sources have both advantages and disadvantages.

Electromagnetic energy is clean. It is not polluting like oil and coal energy sources, nor do we have to destroy the environment to get the raw materials -electrons are everywhere. It has no radioactive components that can explode violently or produce dangerous radioactivity for thousands of years. It also is renewable - we will never run out of electrons or magnetism. Besides being clean and renewable, electricity is versatile. We already know hundreds of ways to use electricity to cool, to heat and to drive motors of all sizes to perform all kinds of work. Electricity can be made to work on extremely small scales, such as in microchips. For packing a lot of information-processing power into a low energy-consuming package there is no other power source that even comes close.

The wireless transmission of electrical power is an idea that goes back to at least the early part of the 20th century. Nikola Tesla (a contemporary of Thomas Edison) worked on the project and discovered the chief disadvantage: It is not easy to achieve. This challenge remains the major disadvantage. Even if it was easy, there is another disadvantage that worries many people: is it safe. Most researchers have concluded that Radio Frequency (RF) waves--the proposed means of transmission--are completely safe and that RF has no affect on living tissue. Not everybody agrees.

New Developments

Electromagnetic power transmission is already a reality on a small scale. Joshua R. Smith, an Intel researcher in Seattle, has developed a device that collects power from ambient RF signals. These signals from radio and television broadcasts largely go to waste. The air is full of these signals. Only a small percent of the energy goes into activating the antennas of interested receivers - the rest goes into trees, houses, the ground or into outer space. Enough of this ambient energy already exists to power a large handheld calculator or an iPhone.

Chemical substance

Steam and liquid water are two different forms of the same chemical substance, water.

In chemistry, a chemical substance is a form of matter that has constant chemical composition and characteristic properties. It cannot be separated into components by physical separation methods, i.e. without breaking chemical bonds. They can be solids, liquids or gases.

Chemical substances are often called 'pure' to set them apart from mixtures. A common example of a chemical substance is pure water; it has the same properties and the same ratio of hydrogen to oxygen whether it is isolated from a river or made in a laboratory. Other chemical substances commonly encountered in pure form are diamond (carbon), gold, salt (sodium chloride) and refined sugar (sucrose). However, simple or seemingly pure substances found in nature can in fact be mixtures of chemical substances. For example, tap water may contain small amounts of dissolved sodium chloride and compounds containing iron, calcium and many other chemical substances.

Chemical substances exist as solids, liquids, gases, or plasma and may change between these phases of matter with changes in temperature or pressure. Chemical reactions convert one chemical substance into another.

In geology, substances of uniform composition are called minerals, while physical mixtures (aggregates) of several minerals (different substances) are defined as rocks. Many minerals, however, mutually dissolve into solid solutions. An element is a chemical substance that is made up of a particular kind of atoms and hence cannot be broken down or transformed by a chemical reaction into a different element, though it can be transmutated into another element through a nuclear reaction. This is so, because all of the atoms in a sample of an element have the same number of protons, though they may be different isotopes, with differing numbers of neutrons.

There are about 120 known elements, about 80 of which are stable – that is, they do not change by radioactive decay into other elements. However, the number of chemical substances that are elements can be more than 120, because some elements can occur as more than a single chemical substance (allotropes). For instance, oxygen exists as both diatomic oxygen (O₂) and ozone (O₃). The majority of elements are classified as metals. These are elements with a characteristic lustre such as iron, copper, and gold. Metals typically conduct electricity and heat well, and they are malleable and ductile. Around a dozen elements, such as carbon, nitrogen, and oxygen, are classified as non-metals. Non-metals lack the metallic properties described above, they also have a high electronegativity and a tendency to form negative ions. Certain elements such as silicon sometimes resemble metals and sometimes resemble non-metals, and are known as metalloids.

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