Ultrafine particleUltrafine particles (UFPs) are particulate matter of nanoscale size (less than 0.1 μm or 100 nm in diameter). Regulations do not exist for this size class of ambient air pollution particles, which are far smaller than the regulated PM10 and PM2.5 particle classes and are believed to have several more aggressive health implications than those classes of larger particulates. In the EU UFP's in ambient air are empirically defined by a technical specification.
Vehicle emission standardEmission standards are the legal requirements governing air pollutants released into the atmosphere. Emission standards set quantitative limits on the permissible amount of specific air pollutants that may be released from specific sources over specific timeframes. They are generally designed to achieve air quality standards and to protect human life. Different regions and countries have different standards for vehicle emissions. Many emissions standards focus on regulating pollutants released by automobiles (motor cars) and other powered vehicles.
PollutantA pollutant or novel entity is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oil) or anthropogenic in origin (i.e. manufactured materials or byproducts). Pollutants result in environmental pollution or become public health concerns when they reach a concentration high enough to have significant negative impacts.
Matrix decompositionIn the mathematical discipline of linear algebra, a matrix decomposition or matrix factorization is a factorization of a matrix into a product of matrices. There are many different matrix decompositions; each finds use among a particular class of problems. In numerical analysis, different decompositions are used to implement efficient matrix algorithms. For instance, when solving a system of linear equations , the matrix A can be decomposed via the LU decomposition.
Zero-emissions vehicleA zero-emission vehicle, or ZEV, is a vehicle that does not emit exhaust gas or other pollutants from the onboard source of power. The California definition also adds that this includes under any and all possible operational modes and conditions. This is because under cold-start conditions for example, internal combustion engines tend to produce the maximum amount of pollutants. In a number of countries and states, transport is cited as the main source of greenhouse gases (GHG) and other pollutants.
Wood-burning stoveA wood-burning stove (or wood burner or log burner in the UK) is a heating or cooking appliance capable of burning wood fuel, often called solid fuel, and wood-derived biomass fuel, such as sawdust bricks. Generally the appliance consists of a solid metal (usually cast iron or steel) closed firebox, often lined by fire brick, and one or more air controls (which can be manually or automatically operated depending upon the stove). The first wood-burning stove was patented in Strasbourg in 1557.
Diesel cycleThe Diesel cycle is a combustion process of a reciprocating internal combustion engine. In it, fuel is ignited by heat generated during the compression of air in the combustion chamber, into which fuel is then injected. This is in contrast to igniting the fuel-air mixture with a spark plug as in the Otto cycle (four-stroke/petrol) engine. Diesel engines are used in aircraft, automobiles, power generation, diesel–electric locomotives, and both surface ships and submarines.
Non-exhaust emissionsNon-exhaust emissions come from wearing down motor vehicle brake pads, tires, roads themselves, and unsettling of particles on the road. This particulate matter is made up of micrometre-sized particles and causes negative health effects, including respiratory disease and cancer. Very fine particulate matter has been linked to cardiovascular disease. Multiple epidemiological studies have demonstrates that particulate matter exposure is associated with acute respiratory infections, lung cancer, and chronic respiratory and cardiovascular disease.
Energy poverty and cookingOne aspect of energy poverty is lack of access to clean, modern fuels and technologies for cooking. As of 2020, more than 2.6 billion people in developing countries routinely cook with fuels such as wood, animal dung, coal, or kerosene. Burning these types of fuels in open fires or traditional stoves causes harmful household air pollution, resulting in an estimated 3.8 million deaths annually according to the World Health Organization (WHO), and contributes to various health, socio-economic, and environmental problems.
Volkswagen emissions scandalThe Volkswagen emissions scandal, sometimes known as Dieselgate or Emissionsgate, began in September 2015, when the United States Environmental Protection Agency (EPA) issued a notice of violation of the Clean Air Act to German automaker Volkswagen Group. The agency had found that Volkswagen had intentionally programmed turbocharged direct injection (TDI) diesel engines to activate their emissions controls only during laboratory emissions testing, which caused the vehicles' output to meet US standards during regulatory testing.
