title: Electric vehicle battery

text: According to a study published in February 2016 by Bloomberg New Energy Finance (BNEF), battery prices fell 65% since 2010, and 35% just in 2015, reaching /kWh. The study concludes that battery costs are on a trajectory to make electric vehicles without government subsidies as affordable as internal combustion engine cars in most countries by 2022. BNEF projects that by 2040, long-range electric cars will cost less than expressed in 2016 dollars. BNEF expects electric car battery costs to be well below /kWh by 2030, and to fall further thereafter as new chemistries become available.


title: Electric vehicle battery

text: In 2010, battery professor Poul Norby stated that he believed that lithium batteries will need to double their specific energy and bring down the price from US$500 (2010) to US$100 per kWh capacity in order to make an impact on petrol cars. Citigroup indicates US$230/kWh.


title: Electric vehicle battery

text: Toyota Prius 2012 plug-in's official page declare of range and a battery capacity of 5.2 kWh with a ratio of /kWh, while the Addax (2015 model) utility vehicle already reaches 110 kilometres (68.5 mi) or a ratio of 7.5 kilometers (4.6 mi)/kWh.


title: Electric vehicle battery

text: United States Secretary of Energy Steven Chu predicted costs for a 40-mile range battery will drop from a price in 2008 of US$12,000 to US$3,600 in 2015 and further to US$1,500 by 2020. lithium-ion, Li-poly, Aluminium-air batteries and zinc-air batteries have demonstrated specific energies high enough to deliver range and recharge times comparable to conventional fossil fueled vehicles.


title: Electric vehicle battery

text: Different costs are important. One issue is purchase price, the other issue is total cost of ownership. As of 2015, electric cars are more expensive to initially purchase, but cheaper to run, and in at least some cases, total cost of ownership may be lower.


title: Electric vehicle battery

text: According to "Kammen et al., 2008", new PEVs would become cost efficient to consumers if battery prices would decrease from US$1300/kWh to about US$500/kWh (so that the battery may pay for itself).


title: Electric vehicle battery

text: In 2010, the Nissan Leaf battery pack was reportedly produced at a cost of US$18,000. Nissan's initial production costs at the launch of the Leaf were therefore about US$750 per kilowatt hour (for the 24 kWh battery).


title: Electric vehicle battery

text: In 2012, McKinsey Quarterly linked battery prices to gasoline prices on a basis of 5-year total cost of ownership for a car, estimating that US$3.50/gallon equates to US$250/kWh. In 2017 McKinsey estimated that electric cars will be competitive at a battery pack cost of US$100/kWh (expected around 2030), and expects pack costs to be US$190/kWh by 2020.


title: Electric vehicle battery

text: In October 2015, car maker GM revealed at their annual Global Business Conference that they expected a price of US$145 per kilowatt hour for Li-ion cells entering 2016.


title: Electric vehicle battery

text: Driving range parity means that the electric vehicle has the same range as an average all-combustion vehicle (), with batteries of specific energy greater than 1 kWh/kg. Higher range means that the electric vehicles would run more kilometers without recharge. Currently, electric vehicle sales are lower than expected due range anxiety - even with the same range as an average all-combustion vehicle, buyers must be assured that there are widely available and compatible charging stations for their vehicles, which are currently not as common as gas stations.


title: Electric vehicle battery

text: Japanese and European Union officials are in talks to jointly develop advanced rechargeable batteries for electric cars to help nations reduce greenhouse-gas emissions. Developing a battery that can power an electric vehicle on a single charging is feasible, said Japanese battery maker GS Yuasa Corp. Sharp Corp and GS Yuasa are among Japanese solar-power cell and battery makers that may benefit from cooperation.


title: Electric vehicle battery

text: Battery pack designs for electric vehicles (EVs) are complex and vary widely by manufacturer and specific application. However, they all incorporate a combination of several simple mechanical and electrical component systems which perform the basic required functions of the pack.


title: Electric vehicle battery

text: The actual battery cells can have different chemistry, physical shapes, and sizes as preferred by various pack manufacturers. Battery packs will always incorporate many discrete cells connected in series and parallel to achieve the total voltage and current requirements of the pack. Battery packs for all electric drive EVs can contain several hundred individual cells. Each cell has a nominal voltage of 3-4 volts, depending on its chemical composition.


title: Electric vehicle battery

text: To assist in manufacturing and assembly, the large stack of cells is typically grouped into smaller stacks called modules. Several of these modules are placed into a single pack. Within each module the cells are welded together to complete the electrical path for current flow. Modules can also incorporate cooling mechanisms, temperature monitors, and other devices. Modules must remain within a specific temperature range for optimal performance. In most cases, modules also allow for monitoring the voltage produced by each battery cell in the stack by using a battery management system (BMS).


title: Electric vehicle battery

text: The battery cell stack has a main fuse which limits the current of the pack under a short circuit. A "service plug" or "service disconnect" can be removed to split the battery stack into two electrically isolated halves. With the service plug removed, the exposed main terminals of the battery present no high potential electrical danger to service technicians.


title: Electric vehicle battery

text: The battery pack also contains relays, or contactors, which control the distribution of the battery pack's electrical power to the output terminals. In most cases there will be a minimum of two main relays which connect the battery cell stack to the main positive and negative output terminals of the pack, which then supply high current to the electrical drive motor. Some pack designs include alternate current paths for pre-charging the drive system through a pre-charge resistor or for powering an auxiliary bus which will also have their own associated control relays. For safety reasons these relays are all normally open.


title: Electric vehicle battery

text: The battery pack also contains a variety of temperature, voltage, and current sensors. Collection of data from the pack sensors and activation of the pack relays are accomplished by the pack's battery monitoring unit (BMU) or BMS. The BMS is also responsible for communications with the vehicle outside the battery pack.


title: Electric vehicle battery

text: Batteries in BEVs must be periodically recharged. BEVs most commonly charge from the power grid (at home or using a street or shop recharging point), which is in turn generated from a variety of domestic resources, such as coal, hydroelectricity, nuclear, natural gas, and others. Home or grid power, such as photovoltaic solar cell panels, wind, or microhydro may also be used and are promoted because of concerns regarding global warming.


title: Electric vehicle battery

text: With suitable power supplies, good battery lifespan is usually achieved at charging rates not exceeding half of the capacity of the battery per hour ("0.5"C""), thereby taking two or more hours for a full charge, but faster charging is available even for large capacity batteries.


title: Electric vehicle battery

text: Charging time at home is limited by the capacity of the household electrical outlet, unless specialized electrical wiring work is done. In the US, Canada, Japan, and other countries with 120V electricity, a normal household outlet delivers 1.5 kilowatts. In other countries with 230V electricity between 7 and 14 kilowatts can be delivered (230V single phase and 400V three-phase, respectively). In Europe, a 400V (three-phase 230V) grid connection is increasingly popular since newer houses don't have natural gas connection due to the European Union's safety regulations.


title: Electric vehicle battery

text: Electric cars like Tesla Model S, Renault Zoe, BMW i3, etc., can recharge their batteries to 80 percent at quick charging stations within 30 minutes. For example, a Tesla Model 3 Long Range charging on a 250 kW Tesla Version 3 Supercharger went from 2% state of charge with of range to 80% state of charge with of range in 27 minutes, which equates to per hour.


title: Electric vehicle battery

text: The charging power can be connected to the car in two ways. The first is a direct electrical connection known as conductive coupling. This might be as simple as a mains lead into a weatherproof socket through special high capacity cables with connectors to protect the user from high voltages. The modern standard for plug-in vehicle charging is the SAE1772 conductive connector (IEC62196 Type1) in the US. The ACEA has chosen the VDE-AR-E 2623-2-2 (IEC62196 Type2) for deployment in Europe, which, without a latch, means unnecessary extra power requirements for the locking mechanism.


title: Electric vehicle battery

text: The second approach is known as inductive charging. A special 'paddle' is inserted into a slot on the car. The paddle is one winding of a transformer, while the other is built into the car. When the paddle is inserted it completes a magnetic circuit which provides power to the battery pack. In one inductive charging system, one winding is attached to the underside of the car, and the other stays on the floor of the garage. The advantage of the inductive approach is that there is no possibility of electrocution as there are no exposed conductors, although interlocks, special connectors and ground fault detectors can make conductive coupling nearly as safe. Inductive charging can also reduce vehicle weight, by moving more charging componentry offboard. An inductive charging advocate from Toyota contended in 1998, that overall cost differences were minimal, while a conductive charging advocate from Ford contended that conductive charging was more cost efficient.


title: Electric vehicle battery

text: Though there are a lot of charging stations worldwide, and the number is only growing, an issue with this is that an EV driver may find themselves at a remote charging station with another vehicle plugged in to the only charger or they may find another vehicle parked in the only EV spot. Currently, no laws prohibit unplugging another person's vehicle, it is simply ruled by etiquette.


title: Electric vehicle battery

text: The range of a BEV depends on the number and type of batteries used. The weight and type of vehicle as well as terrain, weather, and the performance of the driver also have an impact, just as they do on the mileage of traditional vehicles. Electric vehicle conversion performance depends on a number of factors including the battery chemistry:


title: Electric vehicle battery

text: The internal resistance of some batteries may be significantly increased at low temperature which can cause noticeable reduction in the range of the vehicle and on the lifetime of the battery.


title: Electric vehicle battery

text: Finding the economic balance of range versus performance, battery capacity versus weight, and battery type versus cost challenges every EV manufacturer.


title: Electric vehicle battery

text: With an AC system or advanced DC system, regenerative braking can extend range by up to 50% under extreme traffic conditions without complete stopping. Otherwise, the range is extended by about 10 to 15% in city driving, and only negligibly in highway driving, depending upon terrain.


title: Electric vehicle battery

text: BEVs (including buses and trucks) can also use genset trailers and pusher trailers in order to extend their range when desired without the additional weight during normal short range use. Discharged basket trailers can be replaced by recharged ones en route. If rented then maintenance costs can be deferred to the agency.


title: Electric vehicle battery

text: Some BEVs can become Hybrid vehicles depending on the trailer and car types of energy and powertrain.


title: Electric vehicle battery

text: Auxiliary battery capacity carried in trailers can increase the overall vehicle range, but also increases the loss of power arising from aerodynamic drag, increases weight transfer effects and reduces traction capacity.


title: Electric vehicle battery

text: An alternative to recharging is to exchange drained or nearly drained batteries (or battery range extender modules) with fully charged batteries. This is called battery swapping and is done in exchange stations.


title: Electric vehicle battery

text: Zinc-bromine flow batteries can be re-filled using a liquid, instead of recharged by connectors, saving time.


title: Electric vehicle battery

text: There are mainly four stages during the lifecycle of lithium-based EV batteries: the raw materials phase, the battery manufacturing, operation phase and the end-of-life management phase. As shown in the schematic of life cycle of EV batteries, during the first stage, the rare earth materials are extracted in different parts of the world. After they are refined by pre-processing factories, the battery manufacturing companies take over these materials and start to produce batteries and assemble them into packs. These battery packs are then sent to car manufacturing companies for EV integration. In the last stage, if no management is in place, valuable materials in the batteries could be potentially wasted. A good end-of-life management phase will try to close the loop. The used battery packs will either be reused as stationary storage or recycled depending on the battery state of health (SOH).


title: Electric vehicle battery

text: The battery lifecycle is rather long and requires close cooperation between companies and countries. Currently, the raw materials phase and the battery manufacturing and operation phase are well established. The end-of-life management phase is struggled to grow, especially the recycling process mainly because of economics. For example, only 6% of lithium-ion batteries were collected for recycling in 2017–2018 in Australia. However, closing the loop is extremely important. Not only because of a predicted tightened supply of nickel, cobalt and lithium in the future, also recycling EV batteries has the potential to maximize the environmental benefit. Xu et al. predicted that in the sustainable development scenario, lithium, cobalt and nickel will reach or surpass the amount of known reserves in the future if no recycling is in place. Ciez and Whitacre found that by deploying battery recycling some green house gas (GHG) emission from mining could be avoided.


title: Electric vehicle battery

text: To develop a deeper understanding of the lifecycle of EV batteries, it is important to analyze the emission associated with different phases. Using NMC cylindrical cells as an example, Ciez and Whitacre found that around 9 kg COe kg battery"" is emitted during raw materials pre-processing and battery manufacturing under the US average electricity grid. The biggest part of the emission came from materials preparation accounting for more than 50% of the emissions. If NMC pouch cell is used, the total emission increases to almost 10 kg COe kg battery"" while materials manufacturing still contributes to more than 50% of the emission. During the end-of-life management phase, the refurbishing process adds little emission to the lifecycle emission. The recycling process, on the other hand, as suggested by Ciez and Whitacre emits a significant amount of GHG. As shown in the battery recycling emission plot a and c, the emission of the recycling process varies with the different recycling processes, different chemistry and different form factor. Thus, the net emission avoided compared to not recycling also varies with these factors. At a glance, as shown in the plot b and d, the direct recycling process is the most ideal process for recycling pouch cell batteries, while the hydrometallurgical process is most suitable for cylindrical type battery. However, with the error bars shown, the best approach cannot be picked with confidence. It is worth noting that for the lithium iron phosphates (LFP) chemistry, the net benefit is negative. Because LFP cells lacks cobalt and nickel which are expensive and energy intensive to produce, it is more energetically efficient to mine. In general, in addition to promoting the growth of a single sector, a more integrated effort should be in place to reduce the lifecycle emission of EV batteries. A finite total supply of rare earth material can apparently justify the need for recycling. But the environmental benefit of recycling needs closer scrutiny. Based on current recycling technology, the net benefit of recycling depends on the form factors, the chemistry and the recycling process chosen.


title: Electric vehicle battery

text: There are mainly three stages during the manufacturing process of EV batteries: materials manufacturing, cell manufacturing and integration, as shown in Manufacturing process of EV batteries graph in grey, green and orange color respectively. This shown process does not include manufacturing of cell hardware, i.e. casings and current collectors. During the materials manufacturing process, the active material, conductivity additives, polymer binder and solvent are mixed first. After this, they are coated on the current collectors ready for the drying process. During this stage, the methods of making active materials depend on the electrode and the chemistry. For the cathode, two of the most popular chemistry are transition metal oxides, i.e. Lithium nickel manganese cobalt oxides (Li-NMC) and Lithium metal phosphates, i.e. Lithium iron phosphates (LFP). For the anode, the most popular chemistry now is graphite. However, recently there have been a lot of companies started to make Si mixed anode (Sila Nanotech, Prologium) and Li metal anode(Cuberg, Solid Power). In general, for active materials production, there are three steps: materials preparation, materials processing and refinement. Schmuch et al. discussed materials manufacturing in greater details.


title: Electric vehicle battery

text: In the cell manufacturing stage, the prepared electrode will be processed to the desired shape for packaging in a cylindrical, rectangular or pouch format. Then after filling the electrolytes and sealing the cells, the battery cells are cycled carefully to form SEI protecting the anode. Then, these batteries are assembled into packs ready for vehicle integration. Kwade et al. discuss the overall battery manufacturing process in greater detail.


title: Electric vehicle battery

text: When an EV battery pack degrades to 70% to 80% of its original capacity, it is defined to reach the end-of-life. One of the waste management methods is to reuse the pack. By repurposing the pack for stationary storage, more value can be extracted from the battery pack while reducing the per kWh lifecycle impact. However, enabling battery second-life is not easy. Several challenges are hindering the development of the battery refurbishing industry.


title: Electric vehicle battery

text: First, uneven and undesired battery degradation happens during EV operation. Each battery cell could degrade differently during operation. Currently, the state of health (SOH) information from a battery management system (BMS) can be extracted on a pack level. Getting the cell state of health information requires next-generation BMS. In addition, because a lot of factors could contribute to the low SOH at the end of life, such as temperature during operation, charging/discharging pattern and calendar degradation, the degradation mechanism could be different. Thus, just knowing the SOH is not enough to ensure the quality of the refurbished pack. To solve this challenge, engineers can mitigate the degradation by engineering the next-generation thermal management system. To fully understand the degradation inside the battery, computational methods including the first-principle method, physics-based model and machine learning based method should work together to identify the different degradation modes and quantify the level of degradation after severe operations. Lastly, more efficient battery characteristics tools, for instance, electrochemical impedance spectroscopy (EIS) should be used to ensure the quality of the battery pack.


title: Electric vehicle battery

text: Second, it is costly and time-intensive to disassemble modules and cells. Following the last point, the first step is testing to determine the remaining SOH of the battery modules. This operation could vary for each retired system. Next, the module must be fully discharged. Then, the pack must be disassembled and reconfigured to meet the power and energy requirement of the second life application. It is important to note that qualified workers and specialized tools are required to dismantle the high weight and high voltage EV batteries. Besides the solutions discussed in the previous section, a refurbishing company can sell or reuse the discharged energy from the module to reduce the cost of this process. To accelerate the disassembly process, there have been several attempts to incorporate robots in this process. In this case, robots can handle more dangerous task increasing the safety of the dismantling process.


title: Electric vehicle battery

text: Third, battery technology is non-transparent and lacks standards. Because battery development is the core part of EV, it is difficult for the manufacturer to label the exact chemistry of cathode, anode and electrolytes on the pack. In addition, the capacity and the design of the cells and packs changes on a yearly basis. The refurbishing company needs to closely work with the manufacture to have a timely update on this information. On the other hand, government can set up labeling standard.


title: Electric vehicle battery

text: Lastly, the refurbishing process adds cost to the used batteries. Since 2010, the battery costs have decreased by over 85% which is significantly faster than the prediction. Because of the added cost of refurbishing, the refurbished unit may be less attractive than the new batteries to the market.


title: Electric vehicle battery

text: Nonetheless, there have been several successes on the second-life application as shown in the examples of storage projects using second-life EV batteries. They are used in less demanding stationary storage application as peak shaving or additional storage for renewable-based generating sources.


title: Electric vehicle battery

text: Although battery life span can be extended by enabling a second-life application, ultimately EV batteries need to be recycled. Recyclability is not currently an important design consideration for battery manufacturers, and in 2019 only 5% of electric vehicle batteries were recycled. BEV technologies lack an established recycling framework in many countries, making the usage of BEV and other battery-operated electrical equipment a large energy expenditure, ultimately increasing emissions - especially in countries lacking renewable energy resources. Currently, there are five types of recycling processes: Pyrometallurgical recovery, Physical materials separation, Hydrometallurgical metal reclamation, Direct recycling method and Biological metals reclamation. The most widely used processes are the first three processes listed, as shown in the examples of current lithium-ion battery recycling facilities. The last two methods are still on lab or pilot scale, however, they can potentially avoid the largest amount of emission from mining.


title: Electric vehicle battery

text: The pyrometallurgical process involves burning the battery materials with slag, limestone, sand and coke to produce a metal alloy using a high-temperature furnace. The resulted materials are a metallic alloy, slag and gases. The gases comprise molecules that are evaporated from the electrolyte and binder components. The metal alloy can be separated through hydrometallurgical processes into constituent materials. The slag which is a mixture of metals aluminum, manganese and lithium can either be reclaimed by hydrometallurgical processes or used in the cement industry. This process is very versatile and relatively safe. Because there is no pre-sorting needed, it can work with a wide variety of batteries. In addition, because the whole cell is burnt, the metal from the current collectors could help the smelting process and because of the exothermic reaction of burning electrolyte sand plastics the energy consumption can also be reduced. However, this process still requires relatively higher energy consumption and only a limited number of materials can be reclaimed. Physical materials separation recovered materials by mechanical crushing and exploiting physical properties of different components such as particle size, density, ferromagnetism and hydrophobicity. Copper, aluminum and steel casing can be recovered by sorting. The remaining materials, called "black mass", which is composed of nickel, cobalt, lithium and manganese, need a secondary treatment to recover. For the hydrometallurgical process, the cathode materials need to be crushed to remove the current collector. Then, the cathode materials are leached by aqueous solutions to extract the desired metals from cathode materials. Direct cathode recycling as the name suggested extracts the materials directly, yielding a cathode power that is ready to be used as new cathode pristine material. This process involves extracting the electrolyte using liquid or supercritical CO.  After the size of the recovered components is reduced, the cathode materials can be separated out. For the biological metals reclamation or bio-leaching, the process uses microorganisms to digest metal oxides selectively. Then, recyclers can reduce these oxides to produce metal nanoparticles. Although bio-leaching has been used successfully in the mining industry, this process is still nascent to the recycling industry and plenty of opportunities exists for further investigation.


title: Electric vehicle battery

text: There have been many efforts around the world to promote recycling technologies development and deployment. In the US, the Department of Energy Vehicle Technologies Offices (VTO) set up two efforts targeting at innovation and practicability of recycling processes. ReCell Lithium Recycling RD center brings in three universities and three national labs together to develop innovative, efficient recycling technologies. Most notably, the direct cathode recycling method was developed by the ReCell center. On the other hand, VTO also set up the battery recycling prize to incentivize American entrepreneurs to find innovative solutions to solve current challenges.


title: Electric vehicle battery

text: Transition to electric vehicles is estimated to require an 87,000% increase in supply of specific metals by 2060 that need to be mined initially, with recycling (see above) covering part of the demand in future. In the UK alone, it is estimated that switching 31.5 million petrol vehicles to electric would require "207,900 tonnes of cobalt, 264,600 tonnes of lithium carbonate, 7,200 tonnes of neodymium and dysprosium, and 2,362,500 tonnes of copper", and a worldwide switch would require 40 times these amounts. In 2022 the US government planned to give US states $5 billion over five years for electric vehicle chargers. According to IEA 2021 study, mineral supplies need to increase from 400 kilotonnes in 2020 to 11,800 kilotonnes in 2040 in order to cover the demand by EV. This increase creates a number of key challenges, from supply chain (as 60% of production is concentrated in China) to significant impact on climate and environment as result of such a large increase in mining operations.


title: Electric vehicle battery

text: The safety issues of battery electric vehicles are largely dealt with by the international standard ISO 6469. This standard is divided into three parts:


title: Electric vehicle battery

text: Firefighters and rescue personnel receive special training to deal with the higher voltages and chemicals encountered in electric and hybrid electric vehicle accidents. While BEV accidents may present unusual problems, such as fires and fumes resulting from rapid battery discharge, many experts agree that BEV batteries are safe in commercially available vehicles and in rear-end collisions, and are safer than gasoline-propelled cars with rear gasoline tanks.


title: Electric vehicle battery

text: Performance testing simulates the drive cycles for the drive trains of Battery Electric Vehicles (BEV), Hybrid Electric Vehicles (HEV) and Plug in Hybrid Electric Vehicles (PHEV) as per the required specifications of car manufacturers (OEMs). During these drive cycles, controlled cooling of the battery can be performed, simulating the thermal conditions in the car.


title: Electric vehicle battery

text: In addition, climatic chambers control environmental conditions during testing and allow simulation of the full automotive temperature range and climatic conditions.


title: Electric vehicle battery

text: Patents may be used to suppress development or deployment of battery technology. For example, patents relevant to the use of Nickel metal hydride cells in cars were held by an offshoot of Chevron Corporation, a petroleum company, who maintained veto power over any sale or licensing of NiMH technology.


title: Electric vehicle battery

text: As of December 2019, billions of euro in research are planned to be invested around the world for improving batteries.


title: Electric vehicle battery

text: Researchers have come up with some design considerations for contactless BEV chargers. Inductively coupled power transfer (ICPT) systems are made to transfer power efficiently from a primary source (charging station) to one or more secondary sources (BEVs) in a contactless way via magnetic coupling.


title: Electric vehicle battery

text: Europe has plans for heavy investment in electric vehicle battery development and production, and Indonesia also aims to produce electric vehicle batteries in 2023, inviting Chinese battery firm GEM and Contemporary Amperex Technology Ltd to invest in Indonesia.


title: Electric vehicle battery

text: Electric double-layer capacitors (or "ultracapacitors") are used in some electric vehicles, such as AFS Trinity's concept prototype, to store rapidly available energy with their high specific power, in order to keep batteries within safe resistive heating limits and extend battery life.


title: Electric vehicle battery

text: Since commercially available ultracapacitors have a low specific energy, no production electric cars use ultracapacitors exclusively.


title: Electric vehicle battery

text: In January 2020, Elon Musk, CEO of Tesla, stated that the advancements in Li-ion battery technology have made ultra-capacitors unnecessary for electric vehicles.


title: Electric vehicle battery

text: There are several kinds of policy measures to make BEVs more desirable. Purchase-based incentives include a tax rebate or a subsidy when buying or registering a modern BEV. Use based policy measures include providing an exemption for congestion charging for BEV users, allowing BEV users to use bus lanes, or giving free parking to BEVs. These can be classified into local and global policy incentives. Local incentives including congestion charge exemptions or free BEV parking in a city only influence those located in this specific area. Global policy incentives including subsidies or national tax rebates apply to anyone in a country.


title: Electric vehicle battery

text: In 2009, President Barack Obama announced 48 new advanced battery and electric drive projects that would receive US$2.4 billion in funding under the American Recovery and Reinvestment Act. The government claimed that these projects would accelerate the development of U.S. manufacturing capacity for batteries and electric drive components as well as the deployment of electric drive vehicles, helping to establish American leadership in creating the next generation of advanced vehicles.


title: Electric vehicle battery

text: The announcement marked the single largest investment in advanced battery technology for hybrid and electric-drive vehicles ever made. Industry officials expected that this US$2.4 billion investment, coupled with another US$2.4 billion in cost share from the award winners, would result directly in the creation tens of thousands of manufacturing jobs in the U.S. battery and auto industries.


title: Electric vehicle battery

text: The awards cover US$1.5 billion in grants to United States-based manufacturers to produce batteries and their components and to expand battery recycling capacity.


title: Electric vehicle battery

text: On 2 May 2022, President Biden announced the administration will begin a $3.16 billion plan to boost domestic manufacturing and recycling of batteries, in a larger effort to shift the country away from gas-powered cars to electric vehicles. The goal of the Biden administration is to have half of U.S. automobile production electric by 2030.


title: Electric vehicle battery

text: The Inflation Reduction Act, passed August 16, 2022, aimed to incentivize clean energy manufacturing with a $7,500 consumer tax credit for EVs with US-built batteries, and subsidies for EV plants. By October 2022, billions of dollars of investment had been announced for over two dozen US battery plants, leading some commentators to nickname the Midwest as the "Battery Belt."


title: Electric vehicle battery

text: Norway has become a leading example of BEV promotion. The BEV market share is highest in the world in Norway, the main reason being the strong incentives for promoting purchase and ownership of BEVs. Norway has an incentive package for BEVs that often equate or even make a BEV cheaper to purchase than an Internal Combustion Engine Vehicle (ICEV). In addition to the purchase price incentives, there are also incentives that make BEVs more cost-efficient and convenient in daily use. Incentive policies have a clear success for increasing BEV sales in Norway, making it a great case to learn from for other countries wanting to head in the same direction.


title: Gamete

text: A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual that produces the larger type of gamete—called an ovum— and a male produces the smaller type—called a sperm. Sperm cells or spermatozoa are small and motile due to the flagellum, a tail-shaped structure that allows the cell to propel and move. In contrast, each egg cell or ovum is relatively large and non-motile. In short a gamete is an egg cell (female gamete) or a sperm (male gamete). In animals, ova mature in the ovaries of females and sperm develop in the testes of males. During fertilization, a spermatozoon and ovum unite to form a new diploid organism. Gametes carry half the genetic information of an individual, one ploidy of each type, and are created through meiosis, in which a germ cell undergoes two fissions, resulting in the production of four gametes. In biology, the type of gamete an organism produces determines the classification of its sex.


title: Gamete

text: This is an example of anisogamy or heterogamy, the condition in which females and males produce gametes of different sizes (this is the case in humans; the human ovum has approximately 100,000 times the volume of a single human sperm cell). In contrast, isogamy is the state of gametes from both sexes being the same size and shape, and given arbitrary designators for mating type. The name gamete was introduced by the German cytologist Eduard Strasburger. Male and female gametes set the basis for the sexual roles and sexual selection.


title: Gamete

text: Oogenesis is the process of female gamete formation in animals. This process involves meiosis (including meiotic recombination) occurring in the diploid primary oocyte to produce the haploid ovum. Spermatogenesis is the process of male gamete formation in animals. This process also involves meiosis occurring in the diploid primary spermatocyte to produce the haploid spermatozoon.


title: Gamete

text: It is generally accepted that isogamy is the ancestral state from which anisogamy evolved, although its evolution has left no fossil records. Oogamy also evolved from isogamy through anisogamy. There are almost invariably only two gamete types, all analyses showing that intermediate gamete sizes are eliminated due to selection. Intermediate sized gametes do not have the same advantages as small or large ones; they do worse than small ones in mobility and numbers, and worse than large ones in supply.


title: Gamete

text: In contrast to a gamete, a diploid somatic cell of an individual contains one copy of the chromosome set from the sperm and one copy of the chromosome set from the egg cell. Consequently, the cells of the offspring have genes potentially capable of expressing characteristics of both the "father" and the "mother", subject to whether they are dominant or recessive. A gamete's chromosomes are not exact duplicates of either of the sets of chromosomes carried in the diploid chromosomes but a mixture of the two.


title: Gamete

text: Humans and most mammals use the XY sex-determination system in which a normal ovum can carry only an X chromosome whereas a sperm may carry either an X or a Y, while a non-normal sperm cell can end up carrying either no sex-defining chromosomes, an XY pair, or an XX pair; thus the male sperm determines the sex of any resulting zygote. If the zygote has two X chromosomes it will develop into a female, if it has an X and a Y chromosome, it will develop into a male.


title: Gamete

text: For birds, the female ovum determines the sex of the offspring, through the ZW sex-determination system.


title: Gamete

text: Artificial gametes, also known as In vitro derived gametes (IVD), stem cell-derived gametes (SCDGs), and In vitro generated gametes (IVG), are gametes derived from stem cells. The use of such artificial gametes would [QUOTE:] "necessarily require IVF techniques". Research shows that artificial gametes may be a reproductive technique for same-sex male couples, although a surrogate mother would still be required for the gestation period. Women who have passed menopause may be able to produce eggs and bear genetically related children with artificial gametes. Robert Sparrow wrote, in the Journal of Medical Ethics, that embryos derived from artificial gametes could be used to derive new gametes and this process could be repeated to create multiple human generations in the laboratory. This technique could be used to create cell lines for medical applications and for studying the heredity of genetic disorders. Additionally, this technique could be used for human enhancement by selectively breeding for a desired genome or by using recombinant DNA technology to create enhancements that have not arisen in nature.


title: Gamete

text: Plants which reproduce sexually also produce gametes. However, since plants have a life cycle involving alternation of diploid and haploid generations some differences exist. Plants use meiosis to produce spores that develop into multicellular haploid gametophytes which produce gametes by mitosis. The sperm are formed in an organ known as the antheridium and the egg cells in a flask-shaped organ called the archegonium. In flowering plants, the female gametophyte is produced inside the ovule within the ovary of the flower. When mature, the haploid gametophyte produces female gametes which are ready for fertilization. The male gametophyte is produced inside a pollen grain within the anther. When a pollen grain lands on a mature stigma of a flower it germinates to form a pollen tube that grows down the style into the ovary of the flower and then into the ovule. The pollen then produces sperm by mitosis and releases them for fertilization.


title: Zelle (payment service)

text: Zelle () is a United States–based digital payments network owned by Early Warning Services, LLC, a private financial services company owned by the banks Bank of America, Truist, Capital One, JPMorgan Chase, PNC Bank, U.S. Bank, and Wells Fargo. The Zelle service enables individuals to electronically transfer money from their bank account to another registered user's bank account (within the United States) using a mobile device or the website of a participating banking institution.


title: Zelle (payment service)

text: The Zelle instant payment service was launched in June 2017. Previously, the Zelle service was known as clearXchange, which offered payment services through member financial institutions and a website. Launched in April 2011, clearXchange was originally owned by Bank of America, JPMorgan Chase, and Wells Fargo. After Capital One and US Bank joined as partners, clearXchange was sold to Early Warning Services in January 2016. In December 2017, all clearXchange accounts for person-to-person payment services became Zelle accounts.


title: Zelle (payment service)

text: In April 2011, the clearXchange service was launched. It was originally owned and operated by Bank of America, JPMorgan Chase, and Wells Fargo. The service offered person-to-person (P2P), business-to-consumer (B2C), and government-to-consumer (G2C) payments.


title: Zelle (payment service)

text: For person-to-person payments, clearXchange enabled users to send money to other registered users having accounts at participating banks in the United States. Users accessed the network within the websites and apps of member financial institutions, and through clearXchange's website. The network connected with existing bank accounts, so consumers would not need to fund a separate account to use the service. This feature and the lack of fees for using the service were highlighted as advantages for competition with other person-to-person payment services such as PayPal, Popmoney, and Square. The system associated each user bank account with an email address and mobile phone number, so only the recipient's email address or mobile number was needed to send money directly from a bank account to the bank account of another person who had signed up for the service.


title: Zelle (payment service)

text: The number of financial institutions affiliated with clearXchange grew to include other banks and credit unions. Capital One and US Bank were added as additional owner-members.


title: Zelle (payment service)

text: In June 2015, clearXchange announced the availability of a real-time payment system. Some transactions could take as much as five days or longer to be completed.


title: Zelle (payment service)

text: In January 2016, clearXchange was sold to Early Warning Services. Early Warning Services is owned by Bank of America, Truist, Capital One, JPMorgan Chase, PNC Bank, US Bank, and Wells Fargo.


title: Zelle (payment service)

text: In September 2017, Early Warning Services released the Zelle payment system and mobile app and announced that all clearXchange "person-to-person" payment service accounts would be deactivated in December 2017. After that, clearXchange stopped supporting person-to-person payments but has continued to provide payments from companies and government entities to certain customers. The company encouraged the former users of clearXchange to sign up for the new Zelle service. As in the former clearXchange service, payees are identified in the Zelle service by an association between the recipient's bank account and an email address or mobile phone number. Money sent to a registered payee who has an account at a financial institution that is a member of the Zelle network is typically available to the recipient "within minutes".


title: Zelle (payment service)

text: In March 2019, Early Warning Services's CEO, Paul Finch, stepped down to work with the Finch Family Foundation, a Phoenix, Arizona, nonprofit organization that serves needy families and children. Finch cited his long tenure, the completion of the launch of the Zelle network, and the company's plans to start new projects as reasons for the timing of his departure.


title: Zelle (payment service)

text: In May 2019, Early Warning Services appointed their new CEO, Albert Ko, formerly the chief transformation officer for Intuit. While with Intuit, Ko was the general manager for Mint and an overseer of QuickBooks.


title: Zelle (payment service)

text: The Zelle service is intended for payments to those whom the payer already knows and trusts and the service disclaims any responsibility for goods and services sold through the system.


title: Zelle (payment service)

text: Zelle users can send money to other registered Zelle users. (If they attempt to send money to unregistered recipients, the intended recipient will receive an invitation to sign up for the service to complete the transaction.) Users access the network within the websites and apps of Zelle-participating U.S. financial institutions and through the Zelle mobile app. To register with the Zelle mobile app, users must enroll a supported MasterCard or Visa-branded debit card issued in connection with a U.S. bank account.


title: Zelle (payment service)

text: The network connects with existing bank accounts, so consumers do not need to fund a separate account to use the service. Only the recipient's email address or mobile number is needed for a user to send money directly from their bank account to the recipient's bank account.


title: Zelle (payment service)

text: An email address or mobile phone number may only be actively enrolled in Zelle to receive payments at one financial institution. To register at multiple banks, users need to provide different email addresses or mobile phone numbers for each.


title: Zelle (payment service)

text: A Zelle user can transfer money to a recipient or submit a request for others to send a payment or to split the cost of a payment.


title: Zelle (payment service)

text: There are limits on the dollar amount and frequency of transactions allowed on Zelle imposed by the banking institution associated with the account being used. For example, transfers from most Wells Fargo funding accounts are limited to $2,500 per day and $20,000 in a 30-day period, and lower limits may apply for new payees or when using the Zelle mobile app rather than the bank's self-operated services. Transfers from a Chase checking account are limited to $2,000 per day and $16,000 per calendar month.


title: Zelle (payment service)

text: Payments made using Zelle cannot be canceled (unless an attempt was made to send a payment to someone who has not enrolled in the service).


title: Zelle (payment service)

text: The Zelle website launched in June 2017 says that "Transactions between enrolled Zelle users typically occur in minutes. If your recipient is not yet enrolled with Zelle, it may take between 1 and 3 business days after they enroll."


title: Zelle (payment service)

text: The Zelle service's principal competitor is PayPal and its Venmo payment service. Venmo is more popular, based on public awareness, opinion polling, and active engagement with users, but Zelle processes a much larger dollar volume of money transfers — reportedly US$75 billion in its first year, 2017.


title: Zelle (payment service)

text: The two services work very similarly from the user's perspective, "e.g.", both services use email addresses and mobile phone numbers to identify recipients, but Venmo lacks the direct integration with banking institutions that Zelle has and Zelle money transfers are typically processed more quickly.


title: Zelle (payment service)

text: Starting in January 2018, Venmo began to offer a more rapid transfer option than its typical 1–3 day transfer service. Venmo charges a fee for the service, whereas Zelle-affiliated banks do not.


title: Zelle (payment service)

text: The Zelle network does not charge users a fee for money transfers. Banks are allowed to charge a fee for Zelle transfers involving their accounts, but they have generally not chosen to do so.


title: Zelle (payment service)

text: Both Venmo and Zelle payments to a registered user cannot be canceled, though a customer service rep for the company may be able to reverse the transaction with the permission of the recipient.


title: Zelle (payment service)

text: The Zelle Network includes more than 1000 financial institutions, including the network partners MasterCard, Visa, and processor partners such as FIS, Fiserv, and Jack Henry & Associates.


title: Zelle (payment service)

text: The Zelle service has received adverse publicity for fraud incidents in which bank customers' accounts were compromised through social engineering and Zelle then set up by the fraudsters and used to transfer funds out of the victims' accounts, leaving victims with little practical or legal recourse. In some cases, bank customers have been compensated by the banks involved, depending upon the bank and its policies and the specifics of the incident. Banks may use secondary confirmation methods such as SMS or otherwise place limits on newly created accounts and transfers to recently added recipients as a preventive measure. Shortly before releasing a critical report, Senator Elizabeth Warren berated Zelle executives at a September, 2022, Senate Banking Committee hearing, both for lack of refunds in cases of fraud, and lack of response to requests for statistics.


title: 2022 FIFA U-20 Women's World Cup

text: The 2022 FIFA U-20 Women's World Cup () was the 10th edition of the FIFA U-20 Women's World Cup, the biennial international women's youth football championship contested by the under-20 national teams of the member associations of FIFA, since its inception in 2002 as the FIFA U-19 Women's World Championship (the age limit was raised from 19 to 20 in 2008). The tournament was held in Costa Rica, which would have hosted the 2020 edition before it was cancelled due to the COVID-19 pandemic. It was the second time that Costa Rica host a FIFA tournament after the 2014 FIFA U-17 Women's World Cup.


title: 2022 FIFA U-20 Women's World Cup

text: Japan were the defending champions. The opening match played at the tournament was contested between Costa Rica and Australia at Estadio Nacional de Costa Rica, San José. The final was held on 28 August 2022.For the first time on the history of the a FIFA youth tournaments for both men and women, there was a back-to-back final between the two same teams.


title: 2022 FIFA U-20 Women's World Cup

text: Costa Rica and Panama were originally selected as co-hosts of the 2020 FIFA U-20 Women's World Cup on 20 December 2019, before the withdrawal of Panama leaving Costa Rica as the only host country. On 17 November 2020, FIFA announced that the 2020 edition of the tournament would be cancelled due to the COVID-19 pandemic. Instead, Costa Rica was appointed a host of the next edition of the tournament scheduled for 2022.


title: 2022 FIFA U-20 Women's World Cup

text: A total of 16 teams qualify for the final tournament. In addition to Costa Rica who automatically qualifies as host, 15 teams qualify from six continental competitions.


title: 2022 FIFA U-20 Women's World Cup

text: The official draw took place on 5 May 2022, 13:00 local time (), at the Teatro Nacional de Costa Rica in San José. The teams were allocated based on their performances in the 5 previous U-20 Women's World Cups, five bonus points are added to each of the confederation's current champions that won the respective qualifying tournament (for this cycle).


title: 2022 FIFA U-20 Women's World Cup

text: The hosts Costa Rica were automatically seeded and assigned to position A1. Teams of the same confederation could not meet in the group stage.


title: 2022 FIFA U-20 Women's World Cup

text: A total of 13 referees, 26 assistant referees and 14 video match officials (VAR and AVAR) were appointed officially by FIFA for the tournament on 1 June 2022.


title: 2022 FIFA U-20 Women's World Cup

text: The Video assistant referee (VAR) system will be utilize for the first time in a FIFA U-20 Women's World Cup.


title: 2022 FIFA U-20 Women's World Cup

text: The top two teams of each group advanced to the quarter-finals. The format for tiebreakers were determined as follows:


title: 2022 FIFA U-20 Women's World Cup

text: If two or more teams were equal on the basis of the above three criteria, their rankings were determined as follows:


title: 2022 FIFA U-20 Women's World Cup

text: In the knockout stages, if a match was level at the end of normal playing time, extra time would be played (two periods of 15 minutes each) and followed, if necessary, by a penalty shoot-out to determine the winner. However, for the third place match, no extra time will be played and the winner will be determined by a penalty shoot-out if necessary.


title: 2022 FIFA U-20 Women's World Cup

text: Per statistical convention in football, matches decided in extra time are counted as wins and losses, while matches decided by penalty shoot-outs are counted as draws.


title: 2022 FIFA U-20 Women's World Cup

text: The official emblem and slogan were unveiled on 10 August 2021, one year prior to the start of the tournament.


title: 2022 FIFA U-20 Women's World Cup

text: "Vamos juntas" by Isabella Castro, Rebeca Malavassi, Tony Succar and the female choir of the Franz Liszt Schule served as the official song of the tournament. (Produced and composed by Costa Rican artist Jorge Castro).


title: Digital twin

text: A digital twin is a digital representation of an intended or actual real-world physical product, system, or process (a "physical twin") that serves as the effectively indistinguishable digital counterpart of it for practical purposes, such as simulation, integration, testing, monitoring, and maintenance. The digital twin has been intended from its initial introduction to be the underlying premise for Product Lifecycle Management and exists throughout the entire lifecycle, create, build, operate/support, and dispose, of the physical entity it represents. Since information is granular, the digital twin representation is determined by the value based use cases it is created to implement. The digital twin can and does often exist before there is a physical entity. The use of a digital twin in the create phase allows the intended entity's entire lifecycle to be modeled and simulated. A digital twin of an existing entity can, but must not necessarily, be used in real time and regularly synchronized with the corresponding physical system.


title: Digital twin

text: As an example of a real time digital twin, an object being studied — for example, a wind turbine — may be outfitted with various sensors related to vital areas of functionality. These sensors produce data about different aspects of the physical twin’s performance, such as external weather conditions, RPM, and energy output. This data is then relayed to a processing system and applied to the digital twin. Though the concept originated earlier, the first practical definition of a digital twin originated from NASA in an attempt to improve physical-model simulation of spacecraft in 2010. Digital twins are the result of continual improvement in the creation of product design and engineering activities. Product drawings and engineering specifications have progressed from handmade drafting to computer-aided drafting/computer-aided design to model-based systems engineering and strict link to signal from the physical counterpart.


title: Digital twin

text: Digital twins were anticipated by David Gelernter's 1991 book "Mirror Worlds". The concept and model of the digital twin was first publicly introduced in 2002 by Michael Grieves, at a Society of Manufacturing Engineers conference in Troy, Michigan. Grieves proposed the digital twin as the conceptual model underlying product lifecycle management (PLM).


title: Digital twin

text: The digital twin concept, which has been known by different names (e.g., "virtual twin)", was subsequently called the "digital twin" by John Vickers of NASA in a "2010 Roadmap Report". The digital twin concept consists of three distinct parts: the physical object or process and its physical environment, the digital representation of the object or process, and the communication channel between the physical and virtual representations. The connections between the physical version and the digital version include information flows and data that includes physical sensor flows between the physical and virtual objects and environments. The communication connection is referred to as the digital thread.


title: Digital twin

text: The International Council of Systems Engineers (INCOSE) maintains in its Systems Engineering Book of Knowledge (SEBoK) that: "A digital twin is a related yet distinct concept to digital engineering. The digital twin is a high-fidelity model of the system which can be used to emulate the actual system." The evolving US DoD "Digital Engineering Strategy" initiative, first formulated in 2018, defines a digital twin as "an integrated multiphysics, multiscale, probabilistic simulation of an as-built system, enabled by a Digital Thread, that uses the best available models, sensor information, and input data to mirror and predict activities/performance over the life of its corresponding physical twin."


title: Digital twin

text: Digital twins are commonly divided into subtypes that sometimes include: "digital twin prototype" (DTP), "digital twin instance" (DTI), and "digital twin aggregate" (DTA). The DTP consists of the designs, analyses, and processes that realize a physical product. The DTP exists before there is a physical product. The DTI is the digital twin of each individual instance of the product once it is manufactured. The DTI is linked with its physical counterpart from the remainder of the physical counterpart's life. The DTA is the aggregation of DTIs whose data and information can be used for interrogation about the physical product, prognostics, and learning. The specific information contained in the digital twins is driven by use cases. The digital twin is a logical construct, meaning that the actual data and information may be contained in other applications.


title: Digital twin

text: Digital twin technologies have certain characteristics that distinguish them from other technologies:


title: Digital twin

text: One of the main characteristics of digital twin technology is its connectivity. The recent development of the Internet of Things (IoT) brings forward numerous new technologies. The development of IoT also brings forward the development of digital twin technology. This technology shows many characteristics that have similarities with the character of the IoT, namely its connective nature. First and foremost, the technology enables connectivity between the physical component and its digital counterpart. The basis of digital twins is based on this connection, without it, digital twin technology would not exist. As described in the previous section, this connectivity is created by sensors on the physical product which obtain data and integrate and communicate this data through various integration technologies. Digital twin technology enables increased connectivity between organizations, products, and customers. For example, connectivity between partners and customers in a supply chain can be increased by enabling members of this supply chain to check the digital twin of a product or asset. These partners can then check the status of this product by simply checking the digital twin.


title: Digital twin

text: Servitization is the process of organizations that are adding value to their core corporate offerings through services. In the case of the example of engines, the manufacturing of the engine is the core offering of this organization, they then add value by providing a service of checking the engine and offering maintenance.


title: Digital twin

text: Digital twins can be further characterized as a digital technology that is both the consequence and an enabler of the homogenization of data. Due to the fact that any type of information or content can now be stored and transmitted in the same digital form, it can be used to create a virtual representation of the product (in the form of a digital twin), thus decoupling the information from its physical form. Therefore, the homogenization of data and the decoupling of the information from its physical artifact, have allowed digital twins to come into existence. However, digital twins also enable increasingly more information on physical products to be stored digitally and become decoupled from the product itself.


title: Digital twin

text: As data is increasingly digitized, it can be transmitted, stored and computed in fast and low-cost ways. According to Moore's law, computing power will continue to increase exponentially over the coming years, while the cost of computing decreases significantly. This would, therefore, lead to lower marginal costs of developing digital twins and make it comparatively much cheaper to test, predict, and solve problems on virtual representations rather than testing on physical models and waiting for physical products to break before intervening.


title: Digital twin

text: Another consequence of the homogenization and decoupling of information is that the user experience converges. As information from physical objects is digitized, a single artifact can have multiple new affordances. Digital twin technology allows detailed information about a physical object to be shared with a larger number of agents, unconstrained by physical location or time. In his white paper on digital twin technology in the manufacturing industry, Michael Grieves noted the following about the consequences of homogenization enabled by digital twins:


title: Digital twin

text: As stated above, a digital twin enables a physical product to be reprogrammable in a certain way. Furthermore, the digital twin is also reprogrammable in an automatic manner. Through the sensors on the physical product, artificial intelligence technologies, and predictive analytics, A consequence of this reprogrammable nature is the emergence of functionalities. If we take the example of an engine again, digital twins can be used to collect data about the performance of the engine and if needed adjust the engine, creating a newer version of the product. Also, servitization can be seen as a consequence of the reprogrammable nature as well. Manufactures can be responsible for observing the digital twin, making adjustments, or reprogramming the digital twin when needed and they can offer this as an extra service.


title: Digital twin

text: Another characteristic that can be observed, is the fact that digital twin technologies leave digital traces. These traces can be used by engineers for example, when a machine malfunctions to go back and check the traces of the digital twin, to diagnose where the problem occurred. These diagnoses can in the future also be used by the manufacturer of these machines, to improve their designs so that these same malfunctions will occur less often in the future.


title: Digital twin

text: In the sense of the manufacturing industry, modularity can be described as the design and customization of products and production modules. By adding modularity to the manufacturing models, manufacturers gain the ability to tweak models and machines. Digital twin technology enables manufacturers to track the machines that are used and notice possible areas of improvement in the machines. When these machines are made modular, by using digital twin technology, manufacturers can see which components make the machine perform poorly and replace these with better fitting components to improve the manufacturing process.


title: Digital twin

text: An example of digital twins is the use of 3D modeling to create digital companions for the physical objects. It can be used to view the status of the actual physical object, which provides a way to project physical objects into the digital world. For example, when sensors collect data from a connected device, the sensor data can be used to update a "digital twin" copy of the device's state in real time. The term "device shadow" is also used for the concept of a digital twin. The digital twin is meant to be an up-to-date and accurate copy of the physical object's properties and states, including shape, position, gesture, status and motion.


title: Digital twin

text: A digital twin also can be used for monitoring, diagnostics and prognostics to optimize asset performance and utilization. In this field, sensory data can be combined with historical data, human expertise and fleet and simulation learning to improve the outcome of prognostics. Therefore, complex prognostics and intelligent maintenance system platforms can use digital twins in finding the root cause of issues and improve productivity.


title: Digital twin

text: Digital twins of autonomous vehicles and their sensor suite embedded in a traffic and environment simulation have also been proposed as a means to overcome the significant development, testing and validation challenges for the automotive application, in particular when the related algorithms are based on artificial intelligence approaches that require extensive training data and validation data sets.


title: Digital twin

text: The physical manufacturing objects are virtualized and represented as digital twin models (avatars) seamlessly and closely integrated in both the physical and cyber spaces. Physical objects and twin models interact in a mutually beneficial manner.


title: Digital twin

text: The digital twin is disrupting the entire product lifecycle management (PLM), from design, to manufacturing to service and operations. Nowadays, PLM is very time-consuming in terms of efficiency, manufacturing, intelligence, service phases and sustainability in product design. A digital twin can merge the product physical and virtual space. The digital twin enables companies to have a digital footprint of all of their products, from design to development and throughout the entire product life cycle. Broadly speaking, industries with manufacturing business are highly disrupted by digital twins. In the manufacturing process, the digital twin is like a virtual replica of the near-time occurrences in the factory. Thousands of sensors are being placed throughout the physical manufacturing process, all collecting data from different dimensions, such as environmental conditions, behavioural characteristics of the machine and work that is being performed. All this data is continuously communicating and collected by the digital twin.


title: Digital twin

text: Due to the Internet of Things, digital twins have become more affordable and could drive the future of the manufacturing industry. A benefit for engineers lies in real-world usage of products that are virtually being designed by the digital twin. Advanced ways of product and asset maintenance and management come within reach as there is a digital twin of the real 'thing' with real-time capabilities.


title: Digital twin

text: Digital twins offer a great amount of business potential by predicting the future instead of analyzing the past of the manufacturing process. The representation of reality created by digital twins allows manufacturers to evolve towards ex-ante business practices. The future of manufacturing drives on the following four aspects: modularity, autonomy, connectivity and digital twin. As there is an increasing digitalization in the stages of a manufacturing process, opportunities are opening up to achieve a higher productivity. This starts with modularity and leading to higher effectiveness in the production system. Furthermore, autonomy enables the production system to respond to unexpected events in an efficient and intelligent way. Lastly, connectivity like the Internet of Things, makes the closing of the digitalization loop possible, by then allowing the following cycle of product design and promotion to be optimized for higher performance. This may lead to increase in customer satisfaction and loyalty when products can determine a problem before actually breaking down. Furthermore, as storage and computing costs are becoming less expensive, the ways in which digital twins are used are expanding. Implementation challenges such as data integration, organizational or compliance challenges can hinder the implementation of Digital Twins and its benefits.


title: Digital twin

text: Geographic digital twins have been popularised in urban planning practice, given the increasing appetite for digital technology in the Smart Cities movement. These digital twins are often proposed in the form of interactive platforms to capture and display real-time 3D and 4D spatial data in order to model urban environments (cities) and the data feeds within them.


title: Digital twin

text: Visualization technologies such as augmented reality (AR) systems are being used as both collaborative tools for design and planning in the built environment integrating data feeds from embedded sensors in cities and API services to form digital twins. For example, AR can be used to create augmented reality maps, buildings, and data feeds projected onto tabletops for collaborative viewing by built environment professionals.


title: Digital twin

text: In the built environment, partly through the adoption of building information modeling (BIM) processes, planning, design, construction, and operation and maintenance activities are increasingly being digitised, and digital twins of built assets are seen as a logical extension - at an individual asset level and at a national level. In the United Kingdom in November 2018, for example, the Centre for Digital Built Britain published "The Gemini Principles", outlining principles to guide development of a "national digital twin".


title: Digital twin

text: One of the earliest examples of a working 'digital twin' was achieved in 1996 during construction of the Heathrow Express facilities at Heathrow Airport's Terminal 1. Consultant Mott MacDonald and BIM pioneer Jonathan Ingram connected movement sensors in the cofferdam and boreholes to the digital object-model to display movements in the model. A digital grouting object was made to monitor the effects of pumping grout into the earth to stabilise ground movements.


title: Digital twin

text: Digital twins have also been proposed as a method to reduce the need for visual inspections of buildings and infrastructure after earthquakes by using unmanned vehicles to gather data to be added to a virtual model of the affected area.


title: Digital twin

text: Healthcare is recognized as an industry being disrupted by the digital twin technology. The concept of digital twin in the healthcare industry was originally proposed and first used in product or equipment prognostics. With a digital twin, lives can be improved in terms of medical health, sports and education by taking a more data-driven approach to healthcare. The availability of technologies makes it possible to build personalized models for patients, continuously adjustable based on tracked health and lifestyle parameters. This can ultimately lead to a virtual patient, with detailed description of the healthy state of an individual patient and not only on previous records. Furthermore, the digital twin enables individual's records to be compared to the population in order to easier find patterns with great detail. The biggest benefit of the digital twin on the healthcare industry is the fact that healthcare can be tailored to anticipate on the responses of individual patients. Digital twins will not only lead to better resolutions when defining the health of an individual patient but also change the expected image of a healthy patient. Previously, 'healthy' was seen as the absence of disease indications. Now, 'healthy' patients can be compared to the rest of the population in order to really define healthy. However, the emergence of the digital twin in healthcare also brings some downsides. The digital twin may lead to inequality, as the technology might not be accessible for everyone by widening the gap between the rich and poor. Furthermore, the digital twin will identify patterns in a population which may lead to discrimination.


title: Digital twin

text: The automobile industry has been improved by digital twin technology. Digital twins in the automobile industry are implemented by using existing data in order to facilitate processes and reduce marginal costs. Currently, automobile designers expand the existing physical materiality by incorporating software-based digital abilities. A specific example of digital twin technology in the automotive industry is where automotive engineers use digital twin technology in combination with the firm's analytical tool in order to analyze how a specific car is driven. In doing so, they can suggest incorporating new features in the car that can reduce car accidents on the road, which was previously not possible in such a short time frame. Digital twins can be built for not just individual vehicles but also the whole mobility system, where humans (e.g., drivers, passengers, pedestrians), vehicles (e.g., connected vehicles, connected and automated vehicles), and traffics (e.g., traffic networks, traffic infrastructures) can seek guidance from their digital twins deployed on edge/cloud servers to actuate real-time decisions.


title: Pete Holmes

text: Peter Benedict Holmes (born March 30, 1979) is an American comedian, actor, writer, producer, and podcaster. Musings on spirituality and religion are frequent themes in his works.


title: Pete Holmes

text: Holmes gained recognition in the early 2010s as a stand-up comic, during which he launched his long-running podcast "You Made It Weird" (2011–present), released his first comedy special, and worked as an actor and television writer. Subsequently, he began his own late-night talk show "The Pete Holmes Show" (2013–2014), which ran on TBS for two seasons in the time-slot after "Conan", a frequent champion of his work. During the decade, he released four comedy specials: "Impregnated with Wonder" (2011), "Nice Try, The Devil" (2013), "Faces and Sounds" (2016), and "Dirty Clean" (2018).


title: Pete Holmes

text: Holmes is most widely known for starring and creating the semi-autobiographical scripted comedy series "Crashing", which aired on HBO for three seasons (2017–2019). He has also worked as a voice actor and most recently starred in the 2022 CBS sitcom "How We Roll."


title: Pete Holmes

text: Peter Benedict Holmes was born in Boston on March 30, 1979, the son of a Lithuanian refugee mother and an American father of Irish descent. He has a brother who composes music under the name Dr. Holmes. He grew up in Lexington, Massachusetts, where he graduated from Lexington High School. Holmes attended Gordon College in Wenham, Massachusetts, where he graduated with a degree in English and Communications in 2001. During this time, he played in a punk rock band and participated in an improvisational comedy troupe called The Sweaty-Toothed Madmen.


title: Pete Holmes

text: Partly at the behest of his mother, he had plans to become a youth pastor. This gave way to public speaking, and his love for comedy and his devolving faith in God eventually won over his need to preach; he now refers to himself as "Christ-leaning" or jokingly a "hooraytheist". Finding little success as a comedian in his home state, he lived in Sleepy Hollow, New York, before moving to Chicago and then Los Angeles.


title: Pete Holmes

text: Holmes career began in the New York City comedy scene. In the mid-2000s, he was making club appearances and took part in Comedy Central's "Premium Blend", as a regular panelist on VH1's "Best Week Ever", and on VH1's "All Access". He began working as a touring comic, including on the Christian comedy circuit. Since 2006, his cartoons have appeared in "The New Yorker".


title: Pete Holmes

text: Holmes also created and appeared in a Super Bowl XLIII ad for Doritos in 2009 featuring a fictional new flavor of the product, beer, in which each chip contains as much alcohol as a 16 o.z. can of beer.


title: Pete Holmes

text: In 2010, he performed on "John Oliver's New York Stand Up Show" as well as "Late Night with Jimmy Fallon". On February 26, 2010, he performed his first television special on the series "Comedy Central Presents". On March 21, 2011, and on November 17, 2011, he appeared on the TBS talk show "Conan".


title: Pete Holmes

text: Holmes released his first album, "Impregnated With Wonder", on iTunes on November 15, 2011. In 2013, he released his second album, "Nice Try, The Devil".


title: Pete Holmes

text: In 2011, Holmes launch his long-form comedy podcast "You Made It Weird with Pete Holmes". It has featured guests such as Garry Shandling, Judd Apatow, Aziz Ansari, John Mulaney, Ben Schwartz, and Dana Carvey. Topics typically discussed in each episode are the guests' views on comedy, sexuality, and religion.


title: Pete Holmes

text: Holmes has provided the voices for several of the characters on Comedy Central's cartoon "Ugly Americans". He was the voice of the E-Trade baby on several television commercials and was credited as a writer for those commercials.


title: Pete Holmes

text: He wrote for the NBC primetime sitcom "Outsourced" and for the Fox sitcom "I Hate My Teenage Daughter" prior to its cancellation in May 2012.


title: Pete Holmes

text: Holmes has created a comedic portrayal of Batman in CollegeHumor's internet series "Badman". He ran a YouTube channel which was focused around skits alongside Matthew McCarthy called frontpagefilms.


title: Pete Holmes

text: On August 21 and 23 in 2012, Holmes recorded three episodes of a talk show pilot for TBS, produced by Conan O'Brien, entitled "The Midnight Show with Pete Holmes". Holmes's guests on the unaired pilots included Nick Offerman, Joel McHale, T. J. Miller, and Bill Burr. On February 26, 2013, TBS picked up the show and began airing in late 2013. By July 10, 2013, the name of the show was "The Pete Holmes Show". The series premiered on October 28, after "Conan".


title: Pete Holmes

text: The show was picked up for a second season by TBS. On December 9, 2013, Gabe Liedman performed the show's first stand-up routine. On May 23, 2014, TBS canceled the talk show after two seasons following poor audience ratings. The show ended its run on June 19, 2014.


title: Pete Holmes

text: Holmes released his third comedy special, "Faces and Sounds", in 2016. In 2019, he released his fourth album, "Dirty Clean".


title: Pete Holmes

text: Holmes created and stars in the HBO series "Crashing." "Crashing" is a semi-autobiographical show on HBO that revolves around Holmes' character Pete, a young comedian who pursues a career in stand-up comedy after his wife cheats on him, leaving him homeless. Holmes successfully pitched the idea of the show to Judd Apatow and it was picked up by HBO for filming in September 2015, with Apatow as director. The success of the pilot led HBO to give the green-light to the first season in January 2016. After four episodes had aired, HBO renewed the series for a second season which premiered on January 14, 2018. On February 21, 2018, HBO renewed the series for a third season. Although season three was praised by critics, HBO canceled "Crashing" in March 2019.


title: Pete Holmes

text: On May 14, 2019, Holmes released his book "Comedy Sex God", which is described as, "part autobiography, part philosophical inquiry, and part spiritual quest."


title: Pete Holmes

text: On March 29, 2021, Holmes was selected to play the lead role of a laid-off auto worker-turned-professional bowler (based on the life of Tom Smallwood) in a CBS sitcom pilot. On May 14, 2021, the pilot for "Smallwood" was ordered to series, with a mid-season debut planned for the 2021–22 television season. On November 24, CBS announced the sitcom has been retitled "How We Roll", and received an adjusted first-season order of 11 episodes. On December 10, 2021, CBS announced the series would premiere on March 31, 2022. On May 5, 2022, CBS announced the show had been canceled after one season.


title: Pete Holmes

text: Holmes has listed Weird Al, Brian Regan, Sinbad, Steve Martin, Gallagher, Jackie Martling, Conan O'Brien, Jerry Seinfeld, Chris Farley, Dane Cook, and Ray Romano as his biggest comedic influences.


title: Pete Holmes

text: Holmes first married when he was 22 years old; he divorced when he was 28. In late 2017, he married Valerie Chaney. Their daughter was born in September 2018.


title: Australian Senate

text: The Senate is the upper house of the bicameral Parliament of Australia, the lower house being the House of Representatives. The composition and powers of the Senate are established in Chapter I of the Constitution of Australia. There are a total of 76 senators: 12 are elected from each of the six Australian states regardless of population and 2 from each of the two autonomous internal Australian territories (the Australian Capital Territory and the Northern Territory). Senators are popularly elected under the single transferable vote system of proportional representation.


title: Australian Senate

text: Unlike upper houses in other Westminster-style parliamentary systems, the Senate is vested with significant powers, including the capacity to reject all bills, including budget and appropriation bills, initiated by the government in the House of Representatives, making it a distinctive hybrid of British Westminster bicameralism and American-style bicameralism. As a result of proportional representation, the chamber features a multitude of parties vying for power. Since 1981, the governing party or coalition (which needs to maintain the confidence of the lower house) has only had a majority in the Senate from 2005–2007; otherwise, negotiations with other parties and independents have generally been necessary to pass legislation.


title: Australian Senate

text: The Commonwealth of Australia Constitution Act (Imp.) of 1900 established the Senate as part of the system of Dominion government in newly federated Australia. From a comparative governmental perspective, the Australian Senate exhibits distinctive characteristics. Unlike upper Houses in other Westminster system governments, the Senate is not a vestigial body with limited legislative power. Rather it was intended to play – and does play – an active role in legislation. Rather than being modeled solely after the House of Lords, as the Senate of Canada was, the Australian Senate was in part modeled after the United States Senate, by giving equal representation to each state and equal powers with the lower house. The Constitution intended to give less populous states added voice in a Federal legislature, while also providing for the revising role of an upper house in the Westminster system.


title: Australian Senate

text: Although the Prime Minister of Australia and Treasurer of Australia, by convention, are members of the House of Representatives (after John Gorton was appointed prime minister in 1968, he resigned from the Senate and was elected to the House), other members of the Cabinet of Australia may come from either house, and the two Houses have almost equal legislative power. As with most upper chambers in bicameral parliaments, the Senate cannot introduce or amend appropriation bills (bills that authorise government expenditure of public revenue) or bills that impose taxation, that role being reserved for the lower house; it can only approve, reject or defer them. That degree of equality between the Senate and House of Representatives reflects the desire of the Constitution's authors to address smaller states' desire for strong powers for the Senate as a way of ensuring that the interests of more populous states as represented in the House of Representatives did not totally dominate the government. The Australian constitution was enacted before the confrontation in 1909 in Britain between the House of Commons and the House of Lords, which ultimately resulted in the restrictions placed on the powers of the House of Lords by the Parliament Acts 1911 and 1949.


title: Australian Senate

text: In practice, however, most legislation (except for private member's bills) in the Australian Parliament is initiated by the Government, which has control over the lower house. It is then passed to the Senate, which has the opportunity to amend the bill, pass or reject it. In the majority of cases, voting takes place along party lines, although there are occasional conscience votes.


title: Australian Senate

text: The Senate maintains a number of committees, which engage in a wide variety of inquiries. The results have no direct legislative power, but are valuable forums that raise many points of view that would otherwise not receive government or public notice.


title: Australian Senate

text: The system for electing senators has changed several times since Federation. The original arrangement involved a first-past-the-post and block voting or "winner takes all" system, on a state-by-state basis. This was replaced in 1919 by preferential block voting. Block voting tended to produce landslide majorities and even "wipe-outs". For instance, from 1920 to 1923 the Nationalist Party held all but one of the 36 seats, and from 1947 to 1950, the Australian Labor Party held all but three.


title: Australian Senate

text: In 1948, single transferable vote with proportional representation on a state-by-state basis became the method for electing senators. At this time the number of senators was expanded from 36 to 60 and it was argued that a move to proportional representation was needed to even up the balance between both major parties in the chamber. The change in voting systems has been described as an "institutional revolution" that has had the effect of limiting the government's ability to control the chamber, as well as helping the rise of Australian minor parties.


title: Australian Senate

text: The 1984 election saw the introduction of group ticket voting, in order to reduce a high rate of informal voting that arose from the requirement that each candidate be given a preference, and to allow small parties and independent candidates a reasonable chance of winning a seat. This allowed voters to select a single party "Above the Line" to distribute their preferences on their behalf, but voters were still able to vote directly for individual candidates and distribute their own preferences if they wished "Below the Line" by numbering every box.


title: Australian Senate

text: Group tickets were abolished in advance of the 2016 election in order to avoid undue influence of preference deals amongst parties that were seen as distorting election results and a form of optional preferential voting was introduced. As a result of the changes, voters may now assign their preferences for parties above the line (numbering as many boxes as they wish), or individual candidates below the line, and are not required to fill all of the boxes. Both above and below the line voting now use optional preferential voting. For above the line, voters are instructed to number at least their first six preferences; however, a "savings provision" is in place to ensure that ballots will still be counted if less than six are given. For below the line, voters are required to number at least their first 12 preferences. Voters are free to continue numbering as many preferences as they like beyond the minimum number specified. Another savings provision allows ballot papers with at least 6 below the line preferences to be formal. The voting changes make it more difficult for new small parties and independent candidates to be elected to the Senate, but also allow a voter to voluntarily "exhaust" preferences — that is, to ensure their vote cannot flow to specific candidates or parties — if none of the voter's candidate preferences are elected.


title: Australian Senate

text: The changes were subject to a challenge in front of High Court of Australia by sitting South Australian Senator Bob Day of the Family First Party. The senator argued that the changes meant the senators would not be "directly chosen by the people" as required by the constitution. The High Court rejected Day's challenge unanimously, deciding that both above the line and below the line voting were consistent with the constitution.


title: Australian Senate

text: The Australian Senate voting paper under the single transferable vote proportional representation system resembles the following example (shown in two parts), which shows the candidates for Victorian senate representation in the 2016 federal election.


title: Australian Senate

text: Because each state elects six senators at each half-Senate election, the quota for election is only one-seventh or 14.3% (one third or 33.3% for territories, where only two senators are elected). Once a candidate has been elected with votes reaching the quota amount, any votes they receive in addition to this may be distributed to other candidates as preferences, if there are still open seats to fill.


title: Australian Senate

text: With an odd number of seats in a half-Senate election (3 or 5), 50.1% of the vote wins a majority (2/3) or (3/5).


title: Australian Senate

text: With an even number of seats in a half-Senate election (6), 57.1% of the vote is needed to win a majority of seats (4/6).


title: Australian Senate

text: The ungrouped candidates in the far right column do not have a box above the line. Therefore, they can only get a primary (number 1) vote from electors who vote below the line. For this reason, some independents register as a group, either with other independents or by themselves, such as group B in the above example.


title: Australian Senate

text: Names of parties can be shown only if the parties are registered, which requires, among other things, a minimum of 500 members.


title: Australian Senate

text: The order of parties on the ballot papers and the order of ungrouped candidates are determined by a random ballot conducted by the Electoral Commission.


title: Australian Senate

text: Candidates, parties and groups pay a deposit of $2,000 per candidate, which is forfeited if they fail to achieve 4% of the primary vote.


title: Australian Senate

text: Candidates, parties and groups earn a public subsidy if they gain at least 4% of the primary vote. At the 2019 federal election, funding was $2.756 per formal first preference vote.


title: Australian Senate

text: These conditions have periodically been the source of debate, and within these conditions, the composition and rules of the Senate have varied significantly since federation.


title: Australian Senate

text: Under Section 24 of the Constitution, the number of members of the House of Representatives has to be "as nearly as practicable" double the number of senators.


title: Australian Senate

text: The reasons for the nexus are twofold: a desire to maintain a constant influence for the smaller states, and maintain a constant balance of the two Houses in the event of a joint sitting after a double dissolution. A referendum in 1967 to eliminate the nexus was rejected.


title: Australian Senate

text: The size of the Senate has changed over the years. The Constitution originally provided for six senators for each state, resulting in a total of 36 senators.


title: Australian Senate

text: The Constitution permits the Parliament to increase the number of senators, provided that equal numbers of senators from each original state are maintained; accordingly, in 1948, Senate representation was increased from 6 to 10 senators for each state, increasing the total to 60.


title: Australian Senate

text: In 1975, the two territories, the Northern Territory and the Australian Capital Territory, were given an entitlement to elect two senators each for the first time, bringing the number to 64. The senators from the Northern Territory also represent constituents from Australia's Indian Ocean Territories (Christmas Island and the Cocos (Keeling) Islands), while the senators from the Australian Capital Territory also represent voters from the Jervis Bay Territory and since 1 July 2016, Norfolk Island.


title: Australian Senate

text: The latest expansion in Senate numbers took place in 1984, when the number of senators from each state was increased from 10 to 12, resulting in a total of 76 senators.


title: Australian Senate

text: Senators normally serve fixed six-year terms (from 1 July to 30 June). At most federal elections, the seats of 40 of the 76 senators (half of the 72 senators from the six states and all four of the senators from the territories) are contested, along with the entire House of Representatives; such an election is sometimes known as a half-Senate election. The seats of senators representing states elected at a half-Senate election are not contested at the next election, provided it is a half-Senate election. However, under some circumstances, the entire Senate (and the House of Representatives) is dissolved, in what is known as a double dissolution. Following a double dissolution, half the senators representing states serve terms ending on the third 30 June following the election (two to three years) and the rest serve a five to six-year term. Section 13 of the Constitution requires the Senate to allocate long and short terms amongst its members. The term of senators representing a territory expires at the same time as there is an election for the House of Representatives.


title: Australian Senate

text: Section 13 of the Constitution requires that in half-Senate elections, the election of State senators shall take place within one year before the places become vacant. The actual election date is determined by the Governor of each State, who acts on the advice of the State Premier. The Governors almost always act on the recommendation of the Governor-General, with the last independent Senate election writ being issued by the Governor of Queensland during the Gair Affair in 1974.


title: Australian Senate

text: Slightly more than half of the Senate is contested at each general election (half of the 72 state senators, and all four of the territory senators), along with the entire House of Representatives. Except in the case of a double dissolution, senators for the states are elected for fixed terms of six years, commencing on 1 July following the election, and ceasing on 30 June six years later.


title: Australian Senate

text: The term of the four senators from the territories is not fixed, but is defined by the dates of the general elections for the House of Representatives, the period between which can vary greatly, to a maximum of three years and three months. Territory senators commence their terms on the day that they are elected. Their terms expire the day prior to the following general election day.


title: Australian Senate

text: While there is no constitutional requirement for the election of senators to take place at the same time as those for members of the House of Representatives, the government usually synchronises the dates of elections for the Senate and House of Representatives. However, because their terms do not coincide, the incoming Parliament will for some time comprise the new House of Representatives and the old Senate, except for the senators representing the territories, until the new senators start their term on the next 1 July.


title: Australian Senate

text: Following a double dissolution, all 76 senators face re-election. If there is an early House election outside the 12-month period in which Senate elections can occur, the synchronisation of the election will be disrupted, and there can be half-Senate elections without a concurrent House election. The last time this occurred was on 21 November 1970.


title: Australian Senate

text: The number of votes that a candidate must receive to be elected to the senate is referred to as a "quota". The quota is worked out by dividing the number of formal votes by one more than the number of vacancies to be filled and then adding one to the result. The 2019 senate election was a half senate election, so 6 senate vacancies were contested in each state. At this election, the quotas in each state were:


title: Australian Senate

text: Each state elects the same number of senators, meaning there is equal representation for each of the Australian states, regardless of population, so the Senate, like many upper Houses, does not adhere to the principle of "one vote one value". Tasmania, with a population of around 500,000, elects the same number of senators as New South Wales, which has a population of more than 8 million. Because of this imbalance, governments favoured by the more populous states are occasionally frustrated by the extra power the smaller states have in the Senate, to the degree that former Prime Minister Paul Keating famously referred to the Senate's members as "unrepresentative swill". The proportional election system within each state ensures that the Senate incorporates more political diversity than the lower house, which has historically been a two party body. The elected membership of the Senate more closely reflects the first voting preference of the electorate as a whole than does the composition of the House of Representatives, despite the large discrepancies from state to state in the ratio of voters to senators. This often means that the composition of the Senate is different from that of the House of Representatives, contributing to the Senate's function as a house of review.