1.
Natural disaster
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An adverse event will not rise to the level of a disaster if it occurs in an area without vulnerable population. In a vulnerable area, however, such as Nepal during the 2015 earthquake, a landslide is described as an outward and downward slope movement of an abundance of slope-forming materials including rock, soil, artificial, or even a combination of these things. During World War I, an estimated 40,000 to 80,000 soldiers died as a result of avalanches during the campaign in the Alps at the Austrian-Italian front. Many of the avalanches were caused by artillery fire, an earthquake is the result of a sudden release of energy in the Earths crust that creates seismic waves. At the Earths surface earthquakes manifest themselves by vibration, shaking, earthquakes are caused by slippage within geological faults. The underground point of origin of the earthquake is called the seismic focus, the point directly above the focus on the surface is called the epicenter. Earthquakes by themselves rarely kill people or wildlife and it is usually the secondary events that they trigger such as building collapse, fires, tsunamis and volcanoes. Many of these could possibly be avoided by better construction, safety systems, when natural erosion or human mining makes the ground too weak to support the structures built on it, the ground can collapse and produce a sinkhole. Volcanoes can cause destruction and consequent disaster in several ways. The effects include the eruption itself that may cause harm following the explosion of the volcano or falling rocks. Second, lava may be produced during the eruption of a volcano, third, volcanic ash generally meaning the cooled ash – may form a cloud, and settle thickly in nearby locations. When mixed with water forms a concrete-like material. In sufficient quantity ash may cause roofs to collapse under its weight, since the ash has the consistency of ground glass it causes abrasion damage to moving parts such as engines. It is believed that Pompeii was destroyed by a pyroclastic flow, a lahar is a volcanic mudflow or landslide. The 1953 Tangiwai disaster was caused by a lahar, as was the 1985 Armero tragedy in which the town of Armero was buried, a specific type of volcano is the supervolcano. It also killed three-quarters of all plant life in the northern hemisphere, the main danger from a supervolcano is the immense cloud of ash, which has a disastrous global effect on climate and temperature for many years. It is a violent, sudden and destructive change either in quality of water or in distribution or movement of water on land below the surface or in atmosphere. A flood is an overflow of water that submerges land, the EU Floods Directive defines a flood as a temporary covering by water of land which is usually not covered by water
2.
Scanner (radio)
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More often than not, these scanners can also tune to different types of modulation as well. Early scanners were slow, bulky, and expensive, today, modern microprocessors have enabled scanners to store thousands of channels and monitor hundreds of channels per second. Recent models can follow trunked radio systems and decode APCO-P25 digital transmissions, both hand held and desktop models are available. Scanners are often used to police, fire and emergency medical services. Radio scanning serves an important role in the fields of journalism and crime investigation, scanners developed from earlier tunable and fixed-frequency radios that received one frequency at a time. Non-broadcast radio systems, such as used by public safety agencies. With a radio fixed on a frequency, much time could pass between transmissions, while other frequencies might be active. A scanning radio will sequentially monitor multiple programmed channels, or search between user defined frequency limits, the scanner will stop on an active frequency strong enough to break the radios squelch setting and resume scanning other frequencies when that activity ceases. Scanners first became popular and widely available during the heyday of CB radio in the 1970s, the first scanners often had between four and ten channels and required the purchase of a separate crystal for each frequency received. A US patent was issued to Peter W. Pflasterer on June 1,1976, an early 1976 US entry was the Tennelec MCP-1, sold at the January 1976 Consumer Electronics Show in Chicago. Many recent models will allow scanning of the specific DCS or CTCSS code used on a frequency should it have multiple users. One memory bank can be assigned to air traffic control, another can be for local marine communications and these can be switched on and off depending on the users preference. Most scanners have a radio band, allowing the listener to tune into weather radio broadcasts from a NOAA transmitter. Some scanners are equipped with Fire-Tone out, fire tone out decodes Quick Call type tones and acts as a pager when the correct sequence of tones is detected. Modern scanners allow hundreds or thousands of frequencies to be entered via a keypad and stored in various memory banks, active frequencies can be found by searching the internet and frequency reference books or can be discovered through a programmable scanners search function. An external antenna for a scanner or an extendable antenna for a hand held unit will provide greater performance than the original equipment antennas provided by manufacturers. Scanners are used by hobbyists, railfans, auto race fans, aviation enthusiasts, off duty emergency services personnel, many scanner clubs exist to allow members to share information about frequencies, codes and operations. Most have Internet presence, such as websites, email lists or Web forums and it is legal to possess a scanner in Australia
3.
Radio receiver
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In radio communications, a radio receiver is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna, the antenna intercepts radio waves and converts them to tiny alternating currents which are applied to the receiver, and the receiver extracts the desired information. The information produced by the receiver may be in the form of sound, a radio receiver may be a separate piece of electronic equipment, or an electronic circuit within another device. The most familiar form of radio receiver is a broadcast receiver, often just called a radio, the sound is produced either by a loudspeaker in the radio or an earphone which plugs into a jack on the radio. The radio requires electric power, provided either by batteries inside the radio or a cord which plugs into an electric outlet. All radios have a control to adjust the loudness of the audio. The frequency of radio stations is usually listed prominently in their advertising, in order to select a particular station to receive, the radio is adjusted to the frequency of the desired transmitter. In some radios this is done by the user turning a tuning knob until the station is heard in the radios loudspeaker. In most countries radio broadcasting is permitted using two different methods of modulation, that is, methods of adding the signal to the radio wave, AM and FM. In amplitude modulation the strength of the signal is varied by the audio signal. AM broadcasting is permitted on AM broadcast bands between 148 and 283 kHz in the low range and 526 and 1706 kHz in the medium frequency range of the radio spectrum. In frequency modulation the frequency of the signal is varied slightly by the audio signal. FM broadcasting is permitted in the FM broadcast bands between about 65 and 108 MHz in the high frequency range. The exact frequency ranges vary somewhat in different countries, radios sold in each receive the correct frequency range for that country. Most broadcast radios, called AM/FM radios, can receive both AM and FM bands, and have a switch to select which band to receive. Limited AM broadcasting is permitted in parts of the high frequency band called the shortwave band. Shortwave listening requires a receiver that can receive these bands, called a shortwave receiver, at these frequencies, radio waves transmitted into the sky can reflect from a layer in the atmosphere called the ionosphere, returning to earth at transcontinental distances. So shortwaves are used for long distance international broadcasting, often by governmental public service broadcasting organizations like the BBC, due to their lower frequency, AM radio stations can often be received at longer distances than FM stations, at hundreds of miles
4.
Human power
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Human power is work or energy that is produced from the human body. It can also refer to the power of a human, power comes primarily from muscles, but body heat is also used to do work like warming shelters, food, or other humans. World records of performance by humans are of interest to work planners. Human power is used to generate electricity that is stored. Normal human metabolism produces heat at a basal rate of around 80 watts. A trained cyclist can produce about 400 watts of power for an hour or more. A healthy well-fed laborer over the course of an 8-hour work shift can sustain an output of about 75 watts. The yield of electric power is decreased by the inefficiency of the human-powered generator, while some exercise equipment has been fitted with generators, the amount of energy collected is of low value compared to the cost of the conversion equipment. Several forms of transport utilize human power and they include the bicycle, wheelchair, walking, skateboard, wheelbarrow, rowing, skis, and rickshaw. Some forms may utilize more than one person, the historical galley was propelled by freemen or citizens in ancient times, and by slaves captured by pirates in more recent times. The Gossamer Condor was the first human-powered aircraft capable of controlled and sustained flight and it may directly use mechanical power from muscles, or a generator may convert energy generated by the body into electrical power. Such devices contain electrical generators or a system to recharge their batteries. Separate crank-operated generators are now available to recharge battery-powered portable electronic devices such as cell phones, others, such as mechanically powered flashlights, have the generator integrated within the device itself. An alternative to batteries for electricity storage is supercapacitors, now being used in some devices such as the mechanically powered flashlight shown here. Devices that store the energy mechanically, rather than electrically, include Clockwork radios with a mainspring which is wound up by a crank, human-powered devices are useful as emergency equipment, when natural disaster, war, or civil disturbance make regular power supplies unavailable. They have also seen as economical for use in poor countries. They are also a preferable alternative to the use of disposable batteries. Communications is an application for the relatively small amount of electric power that can be generated by a human turning a generator
5.
Battery (electricity)
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An electric battery is a device consisting of one or more electrochemical cells with external connections provided to power electrical devices such as flashlights, smartphones, and electric cars. When a battery is supplying power, its positive terminal is the cathode. The terminal marked negative is the source of electrons that when connected to a circuit will flow. It is the movement of ions within the battery which allows current to flow out of the battery to perform work. Historically the term specifically referred to a device composed of multiple cells. Primary batteries are used once and discarded, the materials are irreversibly changed during discharge. Common examples are the battery used for flashlights and a multitude of portable electronic devices. Secondary batteries can be discharged and recharged multiple times using mains power from a wall socket, examples include the lead-acid batteries used in vehicles and lithium-ion batteries used for portable electronics such as laptops and smartphones. According to a 2005 estimate, the battery industry generates US$48 billion in sales each year. Batteries have much lower energy than common fuels such as gasoline. This is somewhat offset by the efficiency of electric motors in producing mechanical work. The usage of battery to describe a group of electrical devices dates to Benjamin Franklin, alessandro Volta built and described the first electrochemical battery, the voltaic pile, in 1800. This was a stack of copper and zinc plates, separated by brine-soaked paper disks, Volta did not understand that the voltage was due to chemical reactions. Although early batteries were of value for experimental purposes, in practice their voltages fluctuated. It consisted of a pot filled with a copper sulfate solution, in which was immersed an unglazed earthenware container filled with sulfuric acid. These wet cells used liquid electrolytes, which were prone to leakage and spillage if not handled correctly, many used glass jars to hold their components, which made them fragile and potentially dangerous. These characteristics made wet cells unsuitable for portable appliances, near the end of the nineteenth century, the invention of dry cell batteries, which replaced the liquid electrolyte with a paste, made portable electrical devices practical. Batteries convert chemical energy directly to electrical energy, a battery consists of some number of voltaic cells
6.
Flashlight
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A flashlight or a torch, is a portable hand-held electric light. The source of the light is usually an incandescent light bulb or light-emitting diode, a typical flashlight consists of a light bulb mounted in a reflector, a transparent cover to protect the light source and reflector, a battery, and a switch. These are supported and protected by a case, the invention of the dry cell and miniature incandescent electric light bulbs made the first battery-powered flashlights possible around 1899. Today flashlights use mostly incandescent lamps or light-emitting diodes and run on disposable or rechargeable batteries, some are powered by the user turning a crank or shaking the lamp, and some have solar panels to recharge a battery. In addition to the general-purpose hand-held flashlight, many forms have been adapted for special uses, head or helmet-mounted flashlights designed for miners and campers leave the hands free. Some flashlights can be used underwater or in flammable atmospheres, flashlights are used as a light source when in a place with no power. Early flashlights ran on batteries, which could not provide a steady electric current. Because these early flashlights also used energy-inefficient carbon-filament bulbs, resting occurred at short intervals, consequently, they could be used only in brief flashes, hence the common North American name flashlight. The first dry cell battery was invented in 1887, unlike previous batteries, it used a paste electrolyte instead of a liquid. This was the first battery suitable for electrical devices, as it did not spill or break easily. The first mass-produced dry cell batteries came in 1896, and the invention of electric lights soon followed. Portable hand-held electric lights offered advantages in convenience and safety over torches, candles, the electric lamp was odorless, smokeless, and emitted less heat than combustion-powered lighting. It could be turned on and off, and avoided fire risk. On January 10,1899, British inventor David Misell obtained U. S,617,592, assigned to American Electrical Novelty and Manufacturing Company. This electric device designed by Misell was powered by D batteries laid front to back in a tube with the light bulb. The company donated some of these devices to the New York City police, carbon-filament bulbs and fairly crude dry cells made early flashlights an expensive novelty with low sales and low manufacturer interest. Development of the tungsten-filament lamp in 1904, with three times the efficacy of carbon filament types, and improved batteries, made flashlights more useful and popular. The advantage of instant control, and the absence of flame, flashlights became very popular in China, by the end of the 1930s,60 companies made flashlights, some selling for as little as one-third the cost of equivalent imported models
7.
Battery charger
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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 size and 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. Other battery types cannot withstand over-charging, being damaged or overheating or even exploding, a trickle charger provides a relatively small amount of current, only enough to counteract self-discharge of a battery that is idle for a long time. Slow battery chargers may take hours to complete a charge, high-rate chargers may restore most capacity much faster. Such batteries require active monitoring of the battery to protect it from overcharge, 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 often denoted as C or C-rate, any battery has an energy capacity which is given in amp-hours or milliamp-hours. The C-rate is amp or milliamp figure when charging a battery, for example, for a battery with a capacity of 500mAh, the current corresponding to a C-rate of 10 is a charge rate of 5000mA, while the current corresponding to a C-rate of 1/2 is 250mA. Such high charging rates are only with some battery types. Others will be damaged or possibly overheat or catch fire, for example, an automobile SLI lead-acid battery carries several risks of explosion. A simple charger works by supplying a constant DC or pulsed DC power source to a battery being charged, a simple charger typically does not alter its output based on charging time or the charge on the battery. This simplicity means that a simple charger is inexpensive, but there are tradeoffs, typically, a carefully designed simple charger takes longer to charge a battery than otherwise because it is set to use a lower charging rate to prevent damage. Even so, many batteries left on a charger for too long will be weakened or destroyed due to over-charging. These chargers also vary in that they can supply either a constant voltage, or a constant current, simple AC-powered battery chargers usually have much higher ripple current and ripple voltage than other kinds of battery chargers because they are inexpensively designed and built. Generally, when the current is within a batterys manufacturer recommended level. The maximum ripple current for a typical 12 V100 Ah VRLA lead acid battery is 5 amps, as long as the ripple current is not excessive, the expected life of a ripple-charged VRLA battery will be within 3% of the life of a constant DC-charged battery. Fast chargers make use of control circuitry to charge the batteries without damaging any of the cells in the battery. The control circuitry can be built into the battery or in the charging unit. Most such chargers have a fan to help keep the temperature of the cells at safe levels
8.
Siren (alarm)
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A siren is a loud noise making device. Civil defense sirens are mounted in fixed locations and used to warn of natural disasters or attacks, sirens are used on emergency service vehicles such as ambulances, police cars and fire trucks. There are two types, pneumatic and electronic. Many fire sirens serve double duty as tornado or civil defense sirens, most fire sirens are either mounted on the roof of a fire station, or on a pole next to the fire station. Most fire sirens are single tone and mechanically driven by electric motors with an attached to the shaft. Some newer sirens are electronically driven by speakers, though these are not as common, fire sirens are often called fire whistles, fire alarms, or fire horns. Although there is no standard signaling of fire sirens, some utilize codes to inform firefighters of the location of the fire, fire sirens are often blasted once a day at noon and are also called noon sirens or noon whistles. Some time before 1799, the first siren was invented by the Scottish natural philosopher John Robison, robisons sirens were used as musical instruments, specifically, they powered some of the pipes in an organ. Robisons siren consisted of a stopcock that opened and closed a pneumatic tube, the stopcock was apparently driven by the rotation of a wheel. In 1819 an improved siren was invented and named by Baron Charles Cagniard de la Tour, de la Tours siren consisted of two perforated disks that were mounted coaxially at the outlet of a pneumatic tube. One disk was stationary, while the disk rotated. The rotating disk periodically interrupted the flow of air through the fixed disk, de la Tours siren could produce sound under water, suggesting a link with the sirens of Greek mythology, hence the name of the instrument. Instead of disks, most modern sirens use two cylinders, which have slots parallel to their length. The inner cylinder rotates while the outer one remains stationary, as air under pressure flows out of the slots of the inner cylinder and then escapes through the slots of the outer cylinder, the flow is periodically interrupted, creating a tone. The earliest way of summoning volunteer firemen to a fire was by ringing of a bell, either mounted atop the fire station, as electricity became available, the first fire sirens were manufactured. In 1886 French electrical engineer Gustave Trouvé, developed a siren to announce the silent arrival of his electric boats, two early fire sirens were the Decot siren and Sterling Siren. Both started manufacturing fire sirens around 1900 to 1905, many communities have since deactivated their fire sirens as pagers became available for fire department use. During the Second World War the British civil defence used a network of sirens to alert the population to the immanence of an air raid
9.
Territories of the United States
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Territories of the United States are sub-national administrative divisions directly overseen by the United States federal government. These territories are classified by whether they are incorporated and whether they have a government through an Organic Act passed by the U. S. Congress. Currently, the United States has sixteen territories, five of which are inhabited, Puerto Rico, Guam, Northern Mariana Islands, the U. S. Virgin Islands. They are classified as unincorporated territories and they are organized, self-governing territories with locally elected governors and territorial legislatures. Each also elects a member to the U. S. House of Representatives. Eleven territories are small islands, atolls and reefs, spread across the Caribbean and Pacific, the status of some are disputed by Colombia, Haiti, Honduras, Jamaica, Nicaragua, and the Marshall Islands. The Palmyra Atoll is the territory currently incorporated. Historically, territories were created to govern newly acquired land while the borders of the United States were still evolving, other territories administered by the United States went on to become independent countries, such as the Philippines, Micronesia, Marshall Islands and Palau. Many organized incorporated territories of the United States existed from 1789 to 1959, currently, the United States has sixteen territories, five of which are permanently inhabited, Puerto Rico, Guam, Northern Mariana Islands, United States Virgin Islands and American Samoa. The 11 uninhabited territories administered by the Interior Department are Palmyra Atoll, Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, while claimed by the US, Navassa Island, Wake Island, Serranilla Bank and Bajo Nuevo Bank are disputed. Territories have always been a part of the United States, by Act of Congress, the term United States, when used in a geographical sense, means the continental United States, Alaska, Hawaii, Puerto Rico, Guam, and the Virgin Islands of the United States. Since political union with the Northern Mariana Islands in 1986, they too are treated as a part of the U. S, an Executive Order in 2007 includes American Samoa as U. S. geographical extent duly reflected in U. S. State Department documents. Approximately 4 million islanders are U. S. citizens, about 32,000 U. S. non-citizen nationals live in American Samoa, under current law among the territories, only persons born in American Samoa and Swains Island are non-citizen U. S. nationals. American Samoans are under the protection of the U. S. with freedom of U. S. travel without visas. The five inhabited U. S. territories have local voting rights and protections under U. S. courts, pay some U. S. taxes, depending on the congress, they may also vote on the floor in the House Committee of the Whole. S. Every four years, the Democratic and Republican political parties nominate their candidates at conventions which include delegates from the five major territories. The citizens there, however, do not vote in the election for U. S. President. S. Incorporated territories are considered a part of the United States
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