History of underwater diving

John Scott Haldane designed a decompression chamber in 1907 to help make deep-sea divers safer and he produced the first decompression tables for the Royal Navy in 1908 after extensive experiments with animals and human subjects. These tables established a method of decompression in stages - it remains the basis for decompression methods to this day. Following Haldane's recommendation, the maximum safe operating depth for divers was extended to 200 ft. Research on decompression was continued by the US Navy. The C&R tables were published in 1915, and a large number of experimental dives done in the 1930s, which led to the 1937 tables.

Bristol Type 138

Bristol Type 138ABristol 138
Once exhaled, the gas would travel via an external tube to a canister containing carbon dioxide-absorbing chemicals to restore it to a pure oxygen state prior to being re-circulated. The 138 had an internal fuel capacity of 82 gallons, spread across 70 gallons in the lower tank and 12 gallons in the upper tank. A specially-developed fuel, known as S.A.F.4, was used for the altitude record flight, derived from standard grade Shell Ethyl aviation gasoline.

Tyldesley Coal Company

Yew Tree Colliery
An explosion of firedamp caused by a safety lamp cost 25 lives, the youngest 11 and the oldest 35 years of age. Some of the victims are buried in the churchyard at St George's Church. The locomotives owned by the Tyldesley Coal Company had to pass under the Manchester Road bridge which had restricted headroom and were built to a reduced loading gauge. Its first locomotive was a 4-coupled saddle tank locomotive from the Haigh Foundry in Wigan. It was delivered in 1867 and named Tyldesley. Beatrice, another 4-coupled saddle tank, was bought from Vulcan Foundry in Newton le Willows in 1877, the same year that Jessie was delivered from Walker Brothers in Wigan.

Yew Tree Colliery

Yew Tree
An explosion of firedamp, ignited by a safety lamp, in 1858 cost the lives of 25 men and boys. This was the worst mining disaster to occur in Tyldesley. List of Collieries in Astley and Tyldesley. Glossary of coal mining terminology. List of mining disasters in Lancashire.

List of judo techniques

The Kodokan officially also refers to this technique as kuzure-kesa-gatame. 4) Sangaku-Gatame : Triangular Hold . 1) Do-jime : Trunk strangle.

Mine exploration

mine explorersmine
Bad Air: Old mine workings may be hazardous due to pockets of blackdamp (still air with low oxygen levels), or high concentrations of methane, carbon monoxide, carbon dioxide or hydrogen sulfide which can displace oxygen, poison someone outright, or create an explosion. Coal mines are especially prone to containing these gases. The mines of the Comstock Lode Nevada are also very prone to this. Explosives such as dynamite, black powder or blasting caps may have been abandoned in old mines. Many explosives become increasingly unstable with age and could be detonated by the slightest movement or even the vibrations from a footfall.

Nestor Gréhant

Les poisons de l'air, l'acide carbonique et l'oxyde de carbone, 1890 – Poisons of the air, carbon dioxide and carbon monoxide. Les gaz du sang, 1894 – Blood gases. Sur l'emploi du grisoumètre dans les recherches physiologiques, 1894 – On the use of a methanometer in physiological research. Oxyde de carbone, alcool éthylique et grisou, 1903 – Carbon monoxide, ethyl alcohol and firedamp. Hygiène expérimentale: l'oxyde de carbone, 1903 – Experimental hygiene; carbon monoxide.

Gresford Colliery

The miners' appointed Assessor also surmised that a large quantity of gas had accumulated at the top of the face in 14's district, which was then ignited by an accident with a safety lamp or by a spark from a coalcutter. The legal representatives of the pit's management, however, suggested that firedamp had accumulated in the main Dennis haulage road beyond the Clutch (a junction on the main drift where the underground haulage machinery was located) and which was ignited at the Clutch when a telephone was used to warn miners of the influx of gas. This interpretation sought to deny that poor working practices were the ultimate cause of the disaster.

Natural gas

Because burning natural gas produces both water and carbon dioxide, it produces less carbon dioxide per unit of energy released than coal, which produces mostly carbon dioxide. Burning natural gas produces only about half the carbon dioxide per kilowatt-hour (kWh) that coal does. For transportation, burning natural gas produces about 30% less carbon dioxide than burning petroleum.


As carbon dioxide concentrations rise, the rate at which sugars are made by the light-independent reactions increases until limited by other factors. RuBisCO, the enzyme that captures carbon dioxide in the light-independent reactions, has a binding affinity for both carbon dioxide and oxygen. When the concentration of carbon dioxide is high, RuBisCO will fix carbon dioxide. However, if the carbon dioxide concentration is low, RuBisCO will bind oxygen instead of carbon dioxide. This process, called photorespiration, uses energy, but does not produce sugars.


atomsatomic structureatomic
For example, he found that water absorbs carbon dioxide far better than it absorbs nitrogen. Dalton hypothesized this was due to the differences between the masses and configurations of the gases' respective particles, and carbon dioxide molecules (CO 2 ) are heavier and larger than nitrogen molecules (N 2 ). In 1827, botanist Robert Brown used a microscope to look at dust grains floating in water and discovered that they moved about erratically, a phenomenon that became known as "Brownian motion". This was thought to be caused by water molecules knocking the grains about.

Fish physiology

gills of fishguts
These filaments have many functions and "are involved in ion and water transfer as well as oxygen, carbon dioxide, acid and ammonia exchange. Each filament contains a capillary network that provides a large surface area for exchanging oxygen and carbon dioxide. Fish exchange gases by pulling oxygen-rich water through their mouths and pumping it over their gills. In some fish, capillary blood flows in the opposite direction to the water, causing countercurrent exchange. The gills push the oxygen-poor water out through openings in the sides of the pharynx. Fish from multiple groups can live out of the water for extended time periods.

Carbon dioxide in Earth's atmosphere

carbon dioxide emissionsatmospheric carbon dioxideCO 2 emissions
The increased radiative forcing due to increased CO 2 in the Earth's atmosphere is based on the physical properties of CO 2 and the non-saturated absorption windows where CO 2 absorbs outgoing long-wave energy. Atmospheric carbon dioxide plays an integral role in the Earth's carbon cycle whereby carbon dioxide is removed from the atmosphere by some natural processes such as photosynthesis and deposition of carbonates, to form limestones for example, and added back to the atmosphere by other natural processes such as respiration and the acid dissolution of carbonate deposits. There are two broad carbon cycles on Earth: the fast carbon cycle and the slow carbon cycle.

Dry ice

dry-icecarbon dioxidecarbon dioxide ice
Dry ice is the solid form of carbon dioxide (CO 2 ), a molecule consisting of a single carbon atom bonded to two oxygen atoms. Dry ice is colorless, non-flammable, with a sour zesty odor, and can lower the pH of a solution when dissolved in water, forming carbonic acid (H 2 CO 3 ). At pressures below 5.13 atm and temperatures below -56.4 C (the triple point), CO 2 changes from a solid to a gas with no intervening liquid form, through a process called sublimation. The opposite process is called deposition, where CO 2 changes from the gas to solid phase (dry ice). At atmospheric pressure, sublimation/deposition occurs at -78.5 C or 194.65 K.


turfpeat cuttingpeat soil
This leads to lower levels of CO 2 storage than the original peat bog. At 106 g CO 2 /MJ, the carbon dioxide emissions of peat are higher than those of coal (at 94.6 g CO 2 /MJ) and natural gas (at 56.1). According to one study, increasing the average amount of wood in the fuel mixture from the current 2.6% to 12.5% would take the emissions down to 93 g CO 2 /MJ. That said, little effort is being made to achieve this. The International Mire Conservation Group (IMCG) in 2006 urged the local and national governments of Finland to protect and conserve the remaining pristine peatland ecosystems.


Cellular respiration, for instance, is the oxidation of glucose (C 6 H 12 O 6 ) to CO 2 and the reduction of oxygen to water. The summary equation for cell respiration is: : C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O The process of cell respiration also depends heavily on the reduction of NAD + to NADH and the reverse reaction (the oxidation of NADH to NAD + ). Photosynthesis and cellular respiration are complementary, but photosynthesis is not the reverse of the redox reaction in cell respiration: Biological energy is frequently stored and released by means of redox reactions. Photosynthesis involves the reduction of carbon dioxide into sugars and the oxidation of water into molecular oxygen.


coal seamcoal industrycoking coal
The largest and most long term effect of coal use is the release of carbon dioxide, a greenhouse gas that causes climate change and global warming. Coal is the largest contributor to the human-made increase of CO 2 in the atmosphere, 40% of the total. In 2016 world gross carbon dioxide emissions from coal usage were 14.5 giga tonnes. For every megawatt-hour generated, coal-fired electric power generation emits around a tonne of carbon dioxide, which is double the approximately 500 kg of carbon dioxide released by a natural gas-fired electric plant.