
Science
Natural fiber is any fiber that comes from plants, animals, or geological processes. It can be used to make fabrics, composites, and other materials.
Natural fibers are fibers that come from plants, animals, or geological processes. They can be used to make cloth and other materials.
Natural fibers are categorized according to their origin:
- Vegetable fibers are based on arrangements of cellulose. Examples include cotton, flax, hemp, jute, and ramie.
- Wood fibers are also cellulose, but come from trees. Examples include softwood like pine and hardwood like oak.
- Animal fibers consist largely of particular proteins. Examples include silk, wool, angora, and alpaca.
- Mineral fibers are naturally occurring mineral fibers. Examples include asbestos.
Natural fibers have been used for thousands of years for clothing, shelter, tools, and more. They are generally biodegradable and renewable, making them a sustainable alternative to synthetic fibers.
- Nitrogen Fixation: Atmospheric nitrogen (N2), which is unusable by most organisms, is converted into ammonia (NH3) or ammonium (NH4+). This process is primarily carried out by nitrogen-fixing bacteria in the soil and aquatic environments. Some nitrogen fixation also occurs through lightning.
- Nitrification: Ammonia or ammonium is converted into nitrite (NO2-) and then into nitrate (NO3-) by nitrifying bacteria. Nitrate is a form of nitrogen that plants can readily absorb.
- Assimilation: Plants absorb nitrate (NO3-) or ammonium (NH4+) from the soil through their roots. This nitrogen is then incorporated into plant tissues, such as amino acids and nucleic acids. Animals obtain nitrogen by consuming plants or other animals.
- Ammonification: When plants and animals die, or when animals excrete waste, the organic nitrogen in their tissues is converted back into ammonia (NH3) or ammonium (NH4+) by decomposers (bacteria and fungi). This process returns nitrogen to the soil.
- Denitrification: Nitrate (NO3-) is converted back into atmospheric nitrogen (N2) by denitrifying bacteria. This process occurs in anaerobic conditions (oxygen-poor environments) and completes the cycle by returning nitrogen to the atmosphere.
Human activities, such as the use of fertilizers and the burning of fossil fuels, can significantly alter the nitrogen cycle, leading to environmental problems like eutrophication and air pollution.
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The boiling point of water is:
- 212°F (Fahrenheit)
- 100°C (Celsius)
- 373.15 K (Kelvin)
This is the temperature at which water changes from a liquid to a gas (steam) at standard atmospheric pressure.
Keep in mind that the boiling point of water can change based on the surrounding pressure. The boiling point decreases as pressure decreases. For example, at higher altitudes, where the atmospheric pressure is lower, water boils at a lower temperature.