Volatile organic compoundVolatile organic compounds (VOCs) are organic compounds that have a high vapor pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a trait known as volatility. VOCs are responsible for the odor of scents and perfumes as well as pollutants. VOCs play an important role in communication between animals and plants, e.g. attractants for pollinators, protection from predation, and even inter-plant interactions.
Marine ecosystemMarine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply and 90% of habitable space on Earth. Seawater has an average salinity of 35 parts per thousand of water. Actual salinity varies among different marine ecosystems.
ShipA ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally distinguished from boats, based on size, shape, load capacity and purpose. Ships have supported exploration, trade, warfare, migration, colonization, and science. Ship transport is responsible for the largest portion of world commerce.
Environmental effects of shippingThe environmental effects of shipping include air pollution, water pollution, acoustic, and oil pollution. Ships are responsible for more than 18% of nitrogen oxides pollution, and 3% of greenhouse gas emissions. Although ships are the most energy-efficient method to move a given mass of cargo a given distance, the sheer size of the industry means that it has a significant effect on the environment. The annual increasing amount of shipping overwhelms gains in efficiency, such as from slow-steaming.
Cruise shipCruise ships are large passenger ships used mainly for vacationing. Unlike ocean liners, which are used for transport, cruise ships typically embark on round-trip voyages to various ports of call, where passengers may go on tours known as "shore excursions". On "cruises to nowhere" or "nowhere voyages", some cruise ships make two- to three-night round trips without visiting any ports of call. Modern cruise ships tend to have less hull strength, speed, and agility compared to ocean liners.
Mushroom cloudA mushroom cloud is a distinctive mushroom-shaped flammagenitus cloud of debris, smoke, and usually condensed water vapor resulting from a large explosion. The effect is most commonly associated with a nuclear explosion, but any sufficiently energetic detonation or deflagration will produce the same effect. They can be caused by powerful conventional weapons, like thermobaric weapons such as the ATBIP and GBU-43/B MOAB. Some volcanic eruptions and impact events can produce natural mushroom clouds.
Heavy fuel oilHeavy fuel oil (HFO) is a category of fuel oils of a tar-like consistency. Also known as bunker fuel, or residual fuel oil, HFO is the result or remnant from the distillation and cracking process of petroleum. For this reason, HFO is contaminated with several different compounds including aromatics, sulfur and nitrogen, making emissions upon combustion more polluting compared to other fuel oils. HFO is predominantly used as a fuel source for marine vessel propulsion using marine diesel engines due to its relatively low cost compared to cleaner fuel sources such as distillates.
Marine propulsionMarine propulsion is the mechanism or system used to generate thrust to move a watercraft through water. While paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting of an electric motor or internal combustion engine driving a propeller, or less frequently, in pump-jets, an impeller. Marine engineering is the discipline concerned with the engineering design process of marine propulsion systems. Human-powered paddles and oars, and later, sails were the first forms of marine propulsion.
Destructive distillationDestructive distillation is a chemical process in which decomposition of unprocessed material is achieved by heating it to a high temperature; the term generally applies to processing of organic material in the absence of air or in the presence of limited amounts of oxygen or other reagents, catalysts, or solvents, such as steam or phenols. It is an application of pyrolysis. The process breaks up or 'cracks' large molecules.
PanamaxPanamax and New Panamax (or Neopanamax) are terms for the size limits for ships travelling through the Panama Canal. The limits and requirements are published by the Panama Canal Authority (ACP) in a publication titled "Vessel Requirements". These requirements also describe topics like exceptional dry seasonal limits, propulsion, communications, and detailed ship design.
