The United Kingdom the United Kingdom of Great Britain and Northern Ireland, sometimes referred to as Britain, is a sovereign country located off the north-western coast of the European mainland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, many smaller islands. Northern Ireland is the only part of the United Kingdom that shares a land border with another sovereign state, the Republic of Ireland. Apart from this land border, the United Kingdom is surrounded by the Atlantic Ocean, with the North Sea to the east, the English Channel to the south and the Celtic Sea to the south-west, giving it the 12th-longest coastline in the world; the Irish Sea lies between Great Ireland. With an area of 242,500 square kilometres, the United Kingdom is the 78th-largest sovereign state in the world, it is the 22nd-most populous country, with an estimated 66.0 million inhabitants in 2017. The UK is constitutional monarchy; the current monarch is Queen Elizabeth II, who has reigned since 1952, making her the longest-serving current head of state.
The United Kingdom's capital and largest city is London, a global city and financial centre with an urban area population of 10.3 million. Other major urban areas in the UK include Greater Manchester, the West Midlands and West Yorkshire conurbations, Greater Glasgow and the Liverpool Built-up Area; the United Kingdom consists of four constituent countries: England, Scotland and Northern Ireland. Their capitals are London, Edinburgh and Belfast, respectively. Apart from England, the countries have their own devolved governments, each with varying powers, but such power is delegated by the Parliament of the United Kingdom, which may enact laws unilaterally altering or abolishing devolution; the nearby Isle of Man, Bailiwick of Guernsey and Bailiwick of Jersey are not part of the UK, being Crown dependencies with the British Government responsible for defence and international representation. The medieval conquest and subsequent annexation of Wales by the Kingdom of England, followed by the union between England and Scotland in 1707 to form the Kingdom of Great Britain, the union in 1801 of Great Britain with the Kingdom of Ireland created the United Kingdom of Great Britain and Ireland.
Five-sixths of Ireland seceded from the UK in 1922, leaving the present formulation of the United Kingdom of Great Britain and Northern Ireland. There are fourteen British Overseas Territories, the remnants of the British Empire which, at its height in the 1920s, encompassed a quarter of the world's land mass and was the largest empire in history. British influence can be observed in the language and political systems of many of its former colonies; the United Kingdom is a developed country and has the world's fifth-largest economy by nominal GDP and ninth-largest economy by purchasing power parity. It has a high-income economy and has a high Human Development Index rating, ranking 14th in the world, it was the world's first industrialised country and the world's foremost power during the 19th and early 20th centuries. The UK remains a great power, with considerable economic, military and political influence internationally, it is sixth in military expenditure in the world. It has been a permanent member of the United Nations Security Council since its first session in 1946.
It has been a leading member state of the European Union and its predecessor, the European Economic Community, since 1973. The United Kingdom is a member of the Commonwealth of Nations, the Council of Europe, the G7, the G20, NATO, the Organisation for Economic Co-operation and Development and the World Trade Organization; the 1707 Acts of Union declared that the kingdoms of England and Scotland were "United into One Kingdom by the Name of Great Britain". The term "United Kingdom" has been used as a description for the former kingdom of Great Britain, although its official name from 1707 to 1800 was "Great Britain"; the Acts of Union 1800 united the kingdom of Great Britain and the kingdom of Ireland in 1801, forming the United Kingdom of Great Britain and Ireland. Following the partition of Ireland and the independence of the Irish Free State in 1922, which left Northern Ireland as the only part of the island of Ireland within the United Kingdom, the name was changed to the "United Kingdom of Great Britain and Northern Ireland".
Although the United Kingdom is a sovereign country, Scotland and Northern Ireland are widely referred to as countries. The UK Prime Minister's website has used the phrase "countries within a country" to describe the United Kingdom; some statistical summaries, such as those for the twelve NUTS 1 regions of the United Kingdom refer to Scotland and Northern Ireland as "regions". Northern Ireland is referred to as a "province". With regard to Northern Ireland, the descriptive name used "can be controversial, with the choice revealing one's political preferences"; the term "Great Britain" conventionally refers to the island of Great Britain, or politically to England and Wales in combination. However, it is sometimes used as a loose synonym for the United Kingdom as a whole; the term "Britain" is used both as a synonym for Great Britain, as a synonym for the United Kingdom. Usage is mixed, with the BBC preferring to use Britain as shorthand only for Great Britain and the UK Government, while accepting that both terms refer to the United K
Personal digital assistant
A personal digital assistant known as a handheld PC, is a variety mobile device which functions as a personal information manager. PDAs were discontinued in the early 2010s after the widespread adoption of capable smartphones, in particular those based on iOS and Android. Nearly all PDAs have the ability to connect to the Internet. A PDA has an electronic visual display. Most models have audio capabilities, allowing usage as a portable media player, enabling most of them to be used as telephones. Most PDAs can access intranets or extranets via Wi-Fi or Wireless Wide Area Networks. Sometimes, instead of buttons, PDAs employ touchscreen technology; the technology industry has recycled the term personal digital assistance. The term is more used for software that identifies a user's voice to reply to the queries; the first PDA, the Organizer, was released in 1984 by Psion, followed by Psion's Series 3, in 1991. The latter began to resemble the more familiar PDA style, including a full keyboard; the term PDA was first used on January 7, 1992 by Apple Computer CEO John Sculley at the Consumer Electronics Show in Las Vegas, referring to the Apple Newton.
In 1994, IBM introduced the first PDA with full telephone functionality, the IBM Simon, which can be considered the first smartphone. In 1996, Nokia introduced a PDA with telephone functionality, the 9000 Communicator, which became the world's best-selling PDA. Another early entrant in this market was Palm, with a line of PDA products which began in March 1996. A typical PDA has a touchscreen for navigation, a memory card slot for data storage, IrDA, Bluetooth and/or Wi-Fi. However, some PDAs may not have a touchscreen, using softkeys, a directional pad, a numeric keypad or a thumb keyboard for input. To have the functions expected of a PDA, a device's software includes an appointment calendar, a to-do list, an address book for contacts, a calculator, some sort of memo program. PDAs with wireless data connections typically include an email client and a Web browser, may or may not include telephony functionality. Many of the original PDAs, such as the Apple Newton and Palm Pilot, featured a touchscreen for user interaction, having only a few buttons—usually reserved for shortcuts to often-used programs.
Some touchscreen PDAs, including Windows Mobile devices, had a detachable stylus to facilitate making selections. The user interacts with the device by tapping the screen to select buttons or issue commands, or by dragging a finger on the screen to make selections or scroll. Typical methods of entering text on touchscreen PDAs include: A virtual keyboard, where a keyboard is shown on the touchscreen. Text is entered by tapping the on-screen keyboard with stylus. An external keyboard connected via Infrared port, or Bluetooth; some users may choose a chorded keyboard for one-handed use. Handwriting recognition, where letters or words are written on the touchscreen with a stylus, the PDA converts the input to text. Recognition and computation of handwritten horizontal and vertical formulas, such as "1 + 2 =", may be a feature. Stroke recognition allows the user to make a predefined set of strokes on the touchscreen, sometimes in a special input area, representing the various characters to be input.
The strokes are simplified character shapes, making them easier for the device to recognize. One known stroke recognition system is Palm's Graffiti. Despite research and development projects, end-users experience mixed results with handwriting recognition systems; some find it frustrating and inaccurate, while others are satisfied with the quality of the recognition. Touchscreen PDAs intended for business use, such as the BlackBerry and Palm Treo also offer full keyboards and scroll wheels or thumbwheels to facilitate data entry and navigation. Many touchscreen PDAs support some form of external keyboard as well. Specialized folding keyboards, which offer a full-sized keyboard but collapse into a compact size for transport, are available for many models. External keyboards may attach to the PDA directly, using a cable, or may use wireless technology such as infrared or Bluetooth to connect to the PDA. Newer PDAs, such as the HTC HD2, Apple iPhone, Apple iPod Touch, Palm Pre, Palm Pre Plus, Palm Pixi, Palm Pixi Plus, Google Android include more advanced forms of touchscreen that can register multiple touches simultaneously.
These "multi-touch" displays allow for more sophisticated interfaces using various gestures entered with one or more fingers. Although many early PDAs did not have memory card slots, now most have either some form of Secure Digital slot, a CompactFlash slot or a combination of the two. Although designed for memory, Secure Digital Input/Output and CompactFlash cards are available that provide accessories like Wi-Fi or digital cameras, if the device can support them; some PDAs have a USB port for USB flash drives. Some PDAs use microSD cards, which are electronically compatible with SD cards, but have a much smaller physical size. While early PDAs connected to a user's personal computer via serial ports or another proprietary connection, many today connect via a USB cable. Older PDAs were unable to connect to each other via USB, as their implementations of USB didn't support acting as the "host"; some early PDAs were able to connect to the Internet indirectly by means of an external modem connected via the PDA's serial port or "sync" connector, or directly by using an expansion card that provided an Ethernet port.
Most modern PDAs have a popular wireless protocol for mobile devices. Bluetooth can be used to connect keyboards, headsets, GPS receiver
USB is an industry standard that establishes specifications for cables and protocols for connection and power supply between personal computers and their peripheral devices. Released in 1996, the USB standard is maintained by the USB Implementers Forum. There have been three generations of USB specifications: USB 2.0 and USB 3.x. USB was designed to standardize the connection of peripherals like keyboards, pointing devices, digital still and video cameras, portable media players, disk drives and network adapters to personal computers, both to communicate and to supply electric power, it has replaced interfaces such as serial ports and parallel ports, has become commonplace on a wide range of devices. USB connectors have been replacing other types for battery chargers of portable devices; this section is intended to allow fast identification of USB receptacles on equipment. Further diagrams and discussion of plugs and receptacles can be found in the main article above; the Universal Serial Bus was developed to simplify and improve the interface between personal computers and peripheral devices, when compared with existing standard or ad-hoc proprietary interfaces.
From the computer user's perspective, the USB interface improved ease of use in several ways. The USB interface is self-configuring, so the user need not adjust settings on the device and interface for speed or data format, or configure interrupts, input/output addresses, or direct memory access channels. USB connectors are standardized at the host, so any peripheral can use any available receptacle. USB takes full advantage of the additional processing power that can be economically put into peripheral devices so that they can manage themselves; the USB interface is "hot pluggable", meaning devices can be exchanged without rebooting the host computer. Small devices can be powered directly from displacing extra power supply cables; because use of the USB logos is only permitted after compliance testing, the user can have confidence that a USB device will work as expected without extensive interaction with settings and configuration. Installation of a device relying on the USB standard requires minimal operator action.
When a device is plugged into a port on a running personal computer system, it is either automatically configured using existing device drivers, or the system prompts the user to locate a driver, installed and configured automatically. For hardware manufacturers and software developers, the USB standard eliminates the requirement to develop proprietary interfaces to new peripherals; the wide range of transfer speeds available from a USB interface suits devices ranging from keyboards and mice up to streaming video interfaces. A USB interface can be designed to provide the best available latency for time-critical functions, or can be set up to do background transfers of bulk data with little impact on system resources; the USB interface is generalized with no signal lines dedicated to only one function of one device. USB cables are limited in length, as the standard was meant to connect to peripherals on the same table-top, not between rooms or between buildings. However, a USB port can be connected to a gateway.
USB has "master-slave" protocol for addressing peripheral devices. Some extension to this limitation is possible through USB On-The-Go. A host cannot "broadcast" signals to all peripherals at once, each must be addressed individually; some high speed peripheral devices require sustained speeds not available in the USB standard. While converters exist between certain "legacy" interfaces and USB, they may not provide full implementation of the legacy hardware. For a product developer, use of USB requires implementation of a complex protocol and implies an "intelligent" controller in the peripheral device. Developers of USB devices intended for public sale must obtain a USB ID which requires a fee paid to the Implementers' Forum. Developers of products that use the USB specification must sign an agreement with Implementer's Forum. Use of the USB logos on the product require annual fees and membership in the organization. A group of seven companies began the development of USB in 1994: Compaq, DEC, IBM, Microsoft, NEC, Nortel.
The goal was to make it fundamentally easier to connect external devices to PCs by replacing the multitude of connectors at the back of PCs, addressing the usability issues of existing interfaces, simplifying software configuration of all devices connected to USB, as well as permitting greater data rates for external devices. Ajay Bhatt and his team worked on the standard at Intel; the original USB 1.0 specification, introduced in January 1996, defined data transfer rates of 1.5 Mbit/s Low Speed and 12 Mbit/s Full Speed. Microsoft Windows 95, OSR 2.1 provided OEM support for the devices. The first used version of USB was 1.1, released in September 1998. The 12 Mbit/s data rate was intended for higher-speed devices such as disk drives, the lower 1.5 Mbit/s rate for low data
Home energy storage
Home energy storage devices store electricity locally, for consumption. At their heart are batteries lithium-ion or lead-acid, intelligent software. An energy storage technology, they are downstream relatives of battery-based grid energy storage and support the concept of distributed generation; when paired with on-site generation, they can eliminate blackouts in an off-the-grid lifestyle. The stored energy originates from on-site solar photovoltaic panels, generated during daylight hours, the stored electricity consumed after sundown, when domestic energy demand peaks in homes unoccupied during the day. Electric vehicles used during weekdays, needing recharging overnight, are a good fit with home energy storage in homes with solar panels and low daylight-hour electrical consumption. EV manufacturers Tesla, Mercedes-Benz, BMW, Nissan and BYD market own-brand home energy storage devices to their customers, with Tesla's Powerwall enjoying significant media exposure; the units can be programmed to exploit a differential tariff, that provide lower priced energy during hours of low demand - seven hours from 12:30am in the case of Britain’s Economy 7 tariff - for consumption when prices are higher.
Smart tariffs, stemming from the increasing prevalence of smart meters, will be paired with home energy storage devices to exploit low off-peak prices, avoid higher-priced energy at times of peak demand. Transmission of electrical power from power stations to population centres is inherently inefficient, due to transmission losses in electrical grids within power-hungry dense conurbations where power stations are harder to site. By allowing a greater proportion of on-site generated electricity to be consumed on-site, rather than exported to the energy grid, home energy storage devices can reduce the inefficiencies of grid transport. Home energy storage devices, when connected to a server via the internet, can theoretically be ordered to provide short-term services to the energy grid:- Reduced peak hour demand stress - provision of short-term demand response during periods of peak demand reducing the need to inefficiently standing up of short generation assets like diesel generators. Frequency correction - the provision of ultra short-term corrections, to keep mains frequency within the tolerances required by regulators.
Due to the above efficiencies, their ability to boost the amount of solar energy consumed on-site, the devices reduce the amount of power generated using fossil fuels, namely natural gas, coal and diesel. Lithium-ion batteries, a popular choice due to their high charge cycle and lack of memory effect, are difficult to recycle. Lead-acid batteries are easier to recycle and, due to the high resale value of the lead, 99% of those sold in the US get recycled, they have much shorter useful lives than a lithium-ion battery of a similar capacity, due to having a lower charge cycle, narrowing the environmental-impact gap. In addition, lead is a toxic heavy metal and the sulphuric acid in the electrolyte has a high environmental impact. To offset the environmental impact of batteries, some manufacturers extend the useful life of used batteries taken from electric vehicles at the point where the cells won't sufficiently hold charge. Though considered end of life for electric vehicles, the batteries will function satisfactorily in home energy storage devices.
Manufacturers supporting this include BMW and Powervault. Home Energy Storage devices can be paired with salt water batteries, which have a lower environmental impact due to their lack of toxic heavy metal and ease of recyclability. Using a pumped-storage system of cisterns for energy storage and small generators, pico hydro generation may be effective for "closed loop" home energy generation systems. Distributed generation Grid energy storage
Nickel–metal hydride battery
A nickel metal hydride battery, abbreviated NiMH or Ni–MH, is a type of rechargeable battery. The chemical reaction at the positive electrode is similar to that of the nickel–cadmium cell, with both using nickel oxide hydroxide. However, the negative electrodes use a hydrogen-absorbing alloy instead of cadmium. A NiMH battery can have two to three times the capacity of an equivalent size NiCd, its energy density can approach that of a lithium-ion battery. Work on NiMH batteries began at the Battelle-Geneva Research Center following the technology's invention in 1967, it was based on sintered Ti2Ni + TiNi + x NiOOH electrodes. Development was sponsored over nearly two decades by Daimler-Benz and by Volkswagen AG within Deutsche Automobilgesellschaft, now a subsidiary of Daimler AG; the batteries' specific energy reached 50 W·h/kg, power density up to 1000 W/kg and a life of 500 charge cycles. Patent applications were filed in European countries, the United States, Japan; the patents transferred to Daimler-Benz.
Interest grew in the 1970s with the commercialisation of the nickel–hydrogen battery for satellite applications. Hydride technology promised less bulky way to store the hydrogen. Research carried out by Philips Laboratories and France's CNRS developed new high-energy hybrid alloys incorporating rare-earth metals for the negative electrode. However, these suffered from alloy instability in alkaline electrolyte and insufficient cycle life. In 1987, Willems and Buschow demonstrated a successful battery based on this approach, which kept 84% of its charge capacity after 4000 charge–discharge cycles. More economically viable alloys using mischmetal instead of lanthanum were soon developed. Modern NiMH cells were based on this design; the first consumer-grade NiMH cells became commercially available in 1989. In 1998, Ovonic Battery Co. improved the Ti–Ni alloy structure and composition and patented its innovations. In 2008, more than two million hybrid cars worldwide were manufactured with NiMH batteries.
In the European Union and due to its Battery Directive, nickel metal hydride batteries replaced Ni–Cd batteries for portable consumer use. About 22% of portable rechargeable batteries sold in Japan in 2010 were NiMH. In Switzerland in 2009, the equivalent statistic was 60%; this percentage has fallen over time due to the increase in manufacture of lithium-ion batteries: in 2000 half of all portable rechargeable batteries sold in Japan were NiMH. In 2015 BASF produced a modified microstructure that helped make NiMH batteries more durable, in turn allowing changes to the cell design that saved considerable weight, allowing the gravimetric energy density to reach 140 watt-hours per kilogram; the negative electrode reaction occurring in a NiMH cell is H2O + M + e− ⇌ OH− + MHThe charge reaction is read left-to-right and the discharge reaction is read right-to-left. On the positive electrode, nickel oxyhydroxide, NiO, is formed: Ni2 + OH− ⇌ NiO + H2O + e−The metal M in the negative electrode of a NiMH cell is an intermetallic compound.
Many different compounds have been developed for this application, but those in current use fall into two classes. The most common is AB5, where A is a rare-earth mixture of lanthanum, neodymium, B is nickel, manganese, or aluminium; some cells use higher-capacity negative electrode materials based on AB2 compounds, where A is titanium or vanadium, B is zirconium or nickel, modified with chromium, iron, or manganese. Any of these compounds serve the same role; when overcharged at low rates, oxygen produced at the positive electrode passes through the separator and recombines at the surface of the negative. Hydrogen evolution is suppressed, the charging energy is converted to heat; this process allows NiMH cells to be maintenance-free. NiMH cells have an alkaline electrolyte potassium hydroxide; the positive electrode is nickel hydroxide, the negative electrode is hydrogen ions, or protons. The hydrogen ions are stored in a metal-hydride structure, the electrode. Hydrophilic polyolefin nonwovens are used for separation.
Ni/MH batteries of bipolar design are being developed because they offer some advantages for applications as storage systems for electric vehicles. The solid polymer membrane gel separator could be useful for such applications in bipolar design. In other words, this design can help to avoid short-circuits occurring in liquid-electrolyte systems. Charging voltage is in the range of 1.4–1.6 V per cell. In general, a constant-voltage charging method cannot be used for automatic charging; when fast-charging, it is advisable to charge the NiMH cells with a smart battery charger to avoid overcharging, which can damage cells. The simplest of the safe charging methods is with or without a timer. Most manufacturers claim that overcharging is safe at low currents, below 0.1 C. The Panasonic NiMH charging manual warns that overcharging for long enough can damage a battery and suggests limiting the total charging time to 10–20 hours. Duracell further suggests that a trickle charge at C/300 can be used for batteries that must be kept in a charged state.
Some chargers do this after the charge cycle. A similar approach is suggested by Energizer, which indicates that self-catalysis can recombine gas formed at the electrodes for charge rates up to C/10; this leads to cell heating. The company recommends C/30 or C/40 fo
A battery charger, or recharger, is a device used to put energy into a secondary cell or rechargeable battery by forcing an electric current through it. The charging protocol depends on the type of the battery being charged; some battery types have high tolerance for overcharging and can be recharged by connection to a constant voltage source or a constant current source, depending on battery type. Simple chargers of this type must be manually disconnected at the end of the charge cycle, some battery types require, or may use a timer, to cut off charging current at some fixed time when charging is complete. Other battery types cannot withstand over-charging, being damaged, over heating or exploding; the charger may have temperature or voltage sensing circuits and a microprocessor controller to safely adjust the charging current and voltage, determine the state of charge, cut off at the end of charge. A trickle charger provides a small amount of current, only enough to counteract self-discharge of a battery, idle for a long time.
Some battery types cannot tolerate trickle charging of any kind. Lithium ion battery cells use a chemistry system which does not permit indefinite trickle charging.<.ref>Phil Weicker, A Systems Approach to Lithium-Ion Battery Management,Artech House, 2013 ISBN 1608076598 page 26 </ref> Slow battery chargers may take several hours to complete a charge. High-rate chargers may restore most capacity much faster, but high rate chargers can be more than some battery types can tolerate; such batteries require active monitoring of the battery to protect it from overcharging. Electric vehicles ideally need high-rate chargers. For public access, installation of such chargers and the distribution support for them is an issue in the proposed adoption of electric cars. Charge and discharge rates are given as C or C-rate, a measure of the rate at which a battery is charged or discharged relative to its capacity; the C-rate is defined as the charge or discharge current divided by the battery's capacity to store an electrical charge.
While stated explicitly, the unit of the C-rate is h−1, equivalent to stating the battery's capacity to store an electrical charge in unit hour times current in the same unit as the charge or discharge current. The C-rate is never negative, so whether it describes a charging or discharging process depends on the context. For example, for a battery with a capacity of 500 mAh, a discharge rate of 5000 mA corresponds to a C-rate of 10, meaning that such a current can discharge 10 such batteries in one hour. For the same battery a charge current of 250 mA corresponds to a C-rate of 1/2, meaning that this current will increase the state of charge of this battery by 50% in one hour. Since the unit of the C-rate is implied, some care is required when using it to avoid confusing it with the battery's capacity to store a charge, which in the SI has unit coulomb with unit symbol C. If both the charge current and the battery capacity in the C-rate ratio is multiplied by the battery voltage, the C-rate becomes a ratio of the charge power to the battery's energy capacity.
For example, when the 100 kWh battery in a Tesla Model S P100D is undergoing supercharging at 120 kW the C-rate is 1.2 and when that battery delivers its maximum power of 451 kW, its C-rate is 4.51. All charging and discharging of batteries generates internal heat, the amount of heat generated is proportional to the current involved; as some batteries reach their full charge, cooling may be observed. Battery cells which have been built to allow higher C-rates than usual must make provision for increased heating, but high C-ratings are attractive to end users because such batteries can be charged more and produce higher current output in use. High C-rates require the charger to monitor battery parameters such as terminal voltage and temperature to prevent overcharging and so damage to the cells; such high charging rates are possible only with some battery types. Others will be damaged or overheat or catch fire; some batteries may explode. For example, an automobile SLI. A simple charger works by supplying a constant DC or pulsed DC power source to a battery being charged.
A simple charger does not alter its output based on charging time or the charge on the battery. This simplicity means that a simple charger is inexpensive. A designed simple charger takes longer to charge a battery because it is set to use a lower charging rate. So, many batteries left on a simple charger for too long will be weakened or destroyed due to over-charging; these chargers vary in that they can supply either a constant voltage or a constant current, to the battery. Simple AC-powered battery chargers have much higher ripple current and ripple voltage than other kinds of battery chargers because they are inexpensively designed and built; when the ripple current is within a battery's manufacturer recommended level, the ripple voltage will be well within the recommended level. The maximum ripple current for a typical 12 V; as long as the ripple current is not excessive, the expected lif