(As you can guess, different fuels begin burning at different temperatures.) Heat or ignition sources lift fuel (combustible material) to its activation energy to start the fire. The fire generates heat which sustains the chemical reaction; the blaze continues and spreads. Some firefighting tactics shield the fuel from air (oxygen) to extinguish the blaze. Carbon dioxide fire extinguishers expel a cold fog of CO2 that cuts a fire off from its air supply.
The first factor to be considered is the type of the magma. With acidic magma, the magma is very viscous and this can determine how powerful and explosive an eruption is. This is due to the high silica content and low temperature. The more silica in the magma, the thicker and stickier it is. This type of magma is dangerous because it has a tendency to plug the volcano, trapping gasses which build pressure and eventually erupting violently!
Thermal runaway reaction occurs when the heat generated by a reaction goes beyond the heat removal caused by the available cooling capacity. Heat is accumulated leading to a gradual rise in the temperature of the reaction mass; this causes an increase to the rate of reaction and increases the speed of rate of heat generation. [1] Why are thermal runaway reactions dangerous on industrial scale? Thermal runaway reactions are always said to be dangerous on an industrial scale since the reactions go faster in an industry where they tend to reach higher temperatures. As you would already know that exothermic reactions tend to release quite a large amount of heat, so when the reaction mixture gets very warm, a very hot exothermic reaction begins.
Viscosity can be affected by three main factors, Firstly, the higher the temperature, the lower the density of the magma, causing it to flow more easily. Secondly, the greater the amount of dissolved gases in the magma, the less viscous it will be, and lastly the higher the silica content, the more viscous it will be. Thicker, more viscous magma has a greater potential for explosive eruptions and therefore represent the greatest potential hazards. The thickest type of magma is known as Acidic Magma. Its relatively low temperature, high silica content and leads to blockages and powerful eruptions.
Fireworks provide the public with spectacular and mesmerizing explosions that leave the audience in awe, but how do they work? The art of fireworks first originated in ancient China, where the very first firework or firecracker were bamboo shoots filled with gun powder. They were exploded at the start of a new year to scare away evil spirits. Today, modern fireworks are still used in celebrations to mark special occasions. However, throughout the years the mechanics of how fireworks are made slightly became more advanced.
The amount of air pressure depends on how often these particles collide. For a balloon to fly, the air pressure needs to be high, at least as high as the outside air pressure otherwise it would crush it. There are a few ways to increase air pressure including adding more gas particles to increase the frequency of collisions or raising the temperature of the air to speed up the particles which in turn would result in more collisions and greater air pressure. Since it is important that the air is heated up, it also helps if the outside air is cooler so that there does not have to be as many gas particles to create the same high air pressure. Overall, buoyancy and air pressure
This principle is stated in Boyle's Law. Energy for the expansion is drawn from the expanding gas itself, thus causing a lowering of temperature in the gas. Steam engines and turbines, rockets, and internal combustion engines are powered by the expansion of gases. Bread rises in baking because heat expands the carbon dioxide gas it contains. Expansion of Liquids Unlike gases, liquids expand at different rates, depending on their composition.
The fuel and air are mixed outside of the cylinder; once they are both injected they require a spark to ignite. B) A diesel engine uses a much higher compression ration than a gasoline engine. The heat created in a diesel engine by this higher compression is therefore, much greater than
In Ohaake in New Zealand about 320 gm of C02 is produced for each KW hour of electricity produced against 950 to 960 gm. if coal was used. Limitations Geothermal energy is a proven economical resource with energy technology. It has some environmental problems: 1. The steam brings hydrogen sulphide gas to the surface and pollutes the air unless controls are instituted.
Global warming is when the earth heats up (the temperature rises). The causes of these changes Scientists say that the earth’s average temperature could rise by between 2.5 and 10 degrees Fahrenheit by 21002. This would put global average temperatures at the highest levels in thousands of years. It happens when greenhouse gases (carbon dioxide, water vapor, nitrous oxide, and methane) trap heat and light from the sun in the earth’s atmosphere, which increases the temperature. Today, climate change is being driven by the addition of carbon dioxide and other greenhouse gases to the earth's atmosphere at rates faster than the planet's normal mechanisms can adjust to.