Prairies are ecosystems considered part of the temperate grasslands and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, a composition of grasses and shrubs, rather than trees, as the dominant vegetation type. Temperate grassland regions include the Pampas of Argentina and Uruguay, the steppe of Ukraine and Kazakhstan. Lands referred to as "prairie" tend to be in North America; the term encompasses the area referred to as the Interior Lowlands of Canada, the United States, Mexico, which includes all of the Great Plains as well as the wetter, hillier land to the east. In the U. S. the area is constituted by most or all of the states of North Dakota, South Dakota, Nebraska and Oklahoma, sizable parts of the states of Montana, Colorado, New Mexico, Missouri, Illinois, Indiana and western and southern Minnesota. The Palouse of Washington and the Central Valley of California are prairies; the Canadian Prairies occupy vast areas of Manitoba and Alberta. According to Theodore Roosevelt: Prairie is the French word for meadow.

The formation of the North American Prairies started with the uplift of the Rocky Mountains near Alberta. The mountains created a rain shadow; the parent material of most prairie soil was distributed during the last glacial advance that began about 110,000 years ago. The glaciers expanding southward scraped the landscape, picking up geologic material and leveling the terrain; as the glaciers retreated about 10,000 years ago, it deposited this material in the form of till. Wind based loess deposits form an important parent material for prairie soils. Tallgrass prairie evolved over tens of thousands of years with the disturbances of fire. Native ungulates such as bison and white-tailed deer, roamed the expansive, diverse grasslands before European colonization of the Americas. For 10,000-20,000 years, native people used fire annually as a tool to assist in hunting and safety. Evidence of ignition sources of fire in the tallgrass prairie are overwhelmingly human as opposed to lightning. Humans, grazing animals, were active participants in the process of prairie formation and the establishment of the diversity of graminoid and forbs species.

Fire has the effect on prairies of removing trees, clearing dead plant matter, changing the availability of certain nutrients in the soil from the ash produced. Fire kills the vascular tissue of trees, but not prairie species, as up to 75% of the total plant biomass is below the soil surface and will re-grow from its deep roots. Without disturbance, trees will encroach on a grassland and cast shade, which suppresses the understory. Prairie and spaced oak trees evolved to coexist in the oak savanna ecosystem. In spite of long recurrent droughts and occasional torrential rains, the grasslands of the Great Plains were not subject to great soil erosion; the root systems of native prairie grasses held the soil in place to prevent run-off of soil. When the plant died, the fungi, bacteria returned its nutrients to the soil; these deep roots help native prairie plants reach water in the driest conditions. Native grasses suffer much less damage from dry conditions than many farm crops grown. Prairie in North America is split into three groups: wet and dry.

They are characterized by tallgrass prairie, mixed, or shortgrass prairie, depending on the quality of soil and rainfall. In wet prairies, the soil is very moist, including during most of the growing season, because of poor water drainage; the resulting stagnant water is conducive to the formation of fens. Wet prairies have excellent farming soil; the average precipitation is 10–30 inches a year. Mesic prairie good soil during the growing season; this type of prairie is the most converted for agricultural usage. Dry prairie has somewhat wet to dry soil during the growing season because of good drainage in the soil; this prairie can be found on uplands or slopes. Dry soil doesn't get much vegetation due to lack of rain; this is the dominant biome in the Southern Canadian agricultural and climatic region known as Palliser's Triangle. Once thought to be unarable, the Triangle is now one of the most important agricultural regions in Canada thanks to advances in irrigation technology. In addition to its high local importance to Canada, Palliser's Triangle is now one of the most important sources of wheat in the world as a result of these improved methods of watering wheat fields.

Despite these advances in farming technology, the area is still prone to extended periods of drought, which can be disastrous for the industry if it is prolonged. An infamous example of this is the Dust Bowl of the 1930s, which hit much of the United States great plains ecoregion - contributing to the Great Depression. Nomadic hunting has been the main human activity on the prairies for the majority of the archaeological record; this once included many now-extinct species of megafauna. After the other extinction, the main hunted animal on the prairies was the plains bison. Using loud noises and waving large signals, Native peoples would drive bison in fenced pens called to be killed with bows and arrows or spears, or drive them off a cliff, to kill or injure the bison en masse. Th

State of health is a figure of merit of the condition of a battery, compared to its ideal conditions. The units of SoH are percent points. A battery's SoH will be 100% at the time of manufacture and will decrease over time and use. However, a battery's performance at the time of manufacture may not meet its specifications, in which case its initial SoH will be less than 100%. First, a battery management system evaluates the SoH of the battery under its management and reports it; the SoH is compared to a threshold, to determine the suitability of the battery to a given application. Knowing the SoH of a given battery and the SoH threshold of a given application: a determination can be made whether the present battery conditions make it suitable for that application an estimate can be made of the battery's useful lifetime in that application As SoH does not correspond to a particular physical quality, there is no consensus in the industry on how SoH should be determined; the designer of a battery management system may use any of the following parameters to derive an arbitrary value for the SoH.

Internal resistance / impedance / conductance Capacity Voltage Self-discharge Ability to accept a charge Number of charge–discharge cycles Age of the battery Temperature of battery during its previous uses Total energy charged and dischargedIn addition, the designer of the battery management system defines an arbitrary weight for each of the parameter's contribution to the SoH value. The definition of how SoH is evaluated can be a trade secret; as stated before, the method by which the battery management system evaluates the SoH of a battery is arbitrary. The SoH threshold below which an application deems a particular battery unsuitable is arbitrary. Battery balancer Battery charger Battery monitoring Depth of discharge State of charge State of Health Determination Fuzzy logic estimation of SOH of 125Ah VRLA batteries Impedance Data and State of Health

Richard Northalis was an English-born cleric and judge who spent much of his life in Ireland. He held the offices of Archbishop of Dublin and Lord Chancellor of Ireland. For the last decade of his life he was one of the English Crown's most trusted advisers, he was born in Middlesex, the son of John Northale known as John Clarke, Sheriff of London in 1335-6. He entered the Carmelite order in London, he gained a reputation as a preacher of great eloquence, was appointed a royal chaplain. He was Bishop of Ossory from 1386 to 1396, he was a statesman of considerable repute. He was envoy to the Holy See in 1388 and was a trusted adviser to King Richard II in his dealings with the Holy See and in Irish affairs; as a mark of Royal favour he was given an export licence for a wide variety of items, including hawks, falcons and silver. Affairs of state kept him out of Ireland for much of the years 1388-90, during which there appear to have been serious disturbances in his diocese. In 1390 he was given a royal commission to inquire into corruption, maladministration and abuse of office by Irish officials.

The powers granted to him by the commission were wide, no doubt an indication of the high degree of trust placed in him by the Crown. He was entitled to summon any official for questioning. All Crown servants the Lord Lieutenant of Ireland, were required to co-operate with the Bishop; the King in 1391 referred to Richard as a man on whom he relied for his "circumspection and fidelity". He spent much of the summer of that year in England in constant attendance on the King. On his return to Ireland he was made a member of the Privy Council of Ireland and acted as Justiciar of Kilkenny, he was summoned to the Great Council, held in Kilkenny in 1395 where the King, uniquely in the annals of Irish history, was present. He was Lord Chancellor of Ireland from 1393 to 1397. In addition to his judicial duties, he is said to have shouldered much of the burden of government, including the task of keeping the peace between the Gaelic clans and the English settlers, he petitioned the Privy Council for an additional allowance of twenty pounds, complaining that his salary as Lord Chancellor, sixty marks a year, did not cover one third of his expenses.

He worked with James Butler, 3rd Earl of Ormonde, the Lord Lieutenant of Ireland, accompanied him on an armed expedition to Munster. He obtained special leave to visit England without incurring the normal penalties imposed on absentees from Ireland, on condition that he furnish a troop of soldiers for the defence of the realm, he became Archbishop of Dublin in 1396: he died in Dublin died only a year and was buried in St. Patrick's Cathedral. In his short tenure as Archbishop he had one notable achievement: the Archbishop of Dublin was confirmed in office as Admiral of the leading port of Dalkey, south of Dublin city. A number of works are attributed to him, none of which survive: they include Sermones and Ad Ecclesarium Paroches, his authorship of a Hymn to Canute is disputed