Srinivasa Ramanujan

Srinivasa Ramanujan FRS (pronunciation: ⁱ/ʃriːnivɑːsə rɑːmɑːnʊdʒən/) (22 December 1887 – 26 April 1920) was an Indian mathematician and autodidact. Though he had almost no formal training in pure mathematics, he made extraordinary contributions to mathematical analysis, number theory, infinite series, and continued fractions. Ramanujan initially developed his own mathematical research in isolation; it was quickly recognized by Indian mathematicians. When his skills became apparent to the wider mathematical community, centred in Europe at the time, he began a famous partnership with the English mathematician G. H. Hardy. He rediscovered previously known theorems in addition to producing new theorems.

Pythagoras

Pythagoras of Samos (US /pɪˈθæɡərəs/;^[1] UK /paɪˈθæɡərəs/;^[2] Greek: Πυθαγόρας ὁ Σάμιος Pythagóras ho Sámios "Pythagoras the Samian", or simply Πυθαγόρας; Πυθαγόρης in Ionian Greek; c. 570 – c. 495 BC)^[3][4] was anIonian Greek philosopher, mathematician, and has been credited as the founder of the movement calledPythagoreanism. Most of the information about Pythagoras was written down centuries after he lived, so very little reliable information is known about him. He was born on the island of Samos, and traveled, visiting Egypt and Greece, and maybe India, and in 520 BC returned to Samos.^[5] Around 530 BC, he moved to Croton, in Magna Graecia, and there established some kind of school or guild.

Disaster

A disaster is a serious disruption of the functioning of a community or a society involving widespread human, material, economic or environmental losses and impacts, which exceeds the ability of the affected community or society to cope using its own resources.

In contemporary academia, disasters are seen as the consequence of inappropriately managed risk. These risks are the product of a combination of both hazards and vulnerability. Hazards that strike in areas with low vulnerability will never become disasters, as is the case in uninhabited regions.^[1]

Developing countries suffer the greatest costs when a disaster hits – more than 95 percent of all deaths caused by hazards occur in developing countries, and losses due to natural hazards are 20 times greater (as a percentage of GDP) in developing countries than in industrialized countries.^[2][3]

Cyclone Hudhud

Extremely Severe Cyclonic Storm Hudhud^{[nb 1]} was a strong tropical cyclone that caused extensive damage and loss of life in eastern India and Nepal during October 2014.

Hudhud originated from a low pressure system that formed under the influence of an upper-air cyclonic circulation in the Andaman Sea on October 6. Hudhud intensified into a cyclonic storm on October 8 and as a Severe Cyclonic Storm on October 9. Hudhud underwent rapid deepening in the following days and was classified as a Very Severe Cyclonic Storm by the IMD. Shortly before landfall near Visakhapatnam, Andhra Pradesh, on October 12, Hudhud reached its peak strength with three-minute wind speeds of 175 km/h (109 mph) and a minimum central pressure of 960 mbar (28.35 inHg). The system then drifted northwards towards Uttar Pradesh and Nepal, causing widespread rains in both areas and heavy snowfall in the latter.

Cactus

A cactus (plural: cacti, cactuses, or cactus)^[3] is a member of the plant family Cactaceae within the order Caryophyllales. The word "cactus" derives, through Latin, from the Ancient Greek κάκτος, kaktos, a name originally used by Theophrastusfor a spiny plant whose identity is not certain.^[4] Cacti occur in a wide range of shapes and sizes. Most cacti live in habitats subject to at least some drought. Many live in extremely dry environments, even being found in the Atacama Desert, one of the driest places on earth. Cacti show many adaptations to conserve water. Almost all cacti are succulents, meaning they have thickened, fleshy parts adapted to store water. Unlike many other succulents, the stem is the only part of most cacti where this vital process takes place. Most species of cacti have lost true leaves, retaining only spines, which are highly modified leaves. As well as defending against herbivores, spines help prevent water loss by reducing air flow close to the cactus and providing some shade. In the absence of leaves, enlarged stems carry out photosynthesis. Cacti are native to the Americas, ranging from Patagonia in the south to parts of western Canada in the north—except for Rhipsalis baccifera, which also grows in Africa and Sri Lanka.

Lotus (genus)

Lotus, derived from lota (a small, usually spherical water vessel of brass, copper or plastic used in parts of South Asia), is agenus that included bird's-foot trefoils (also known as bacon-and-eggs^[1]) and deervetches^[2] and contains many dozens of species distributed world-wide. Depending on the taxonomic authority, roughly between 70 and 150 are accepted. Lotus is a genus of legume and its members are adapted to a wide range of habitats, from coastal environments to high altitudes. Most species have leaves with five leaflets; two of these are at the extreme base of the leaf, with the other three at the tip of a naked midrib. This gives the appearance of a pair of large stipules below a "petiole" bearing a trefoil of three leaflets – in fact, the true stipules are minute, soon falling or withering.^[3] Some species have pinnate leaves with up to 15 leaflets. Theflowers are in clusters of three to ten together at the apex of a stem with some basal leafy bracts; they are pea-flower shaped, usually vivid yellow, but occasionally orange or red. The seeds develop in three or four straight, strongly diverging pods, which together make a shape reminiscent of the diverging toes of a small bird, leading to the common name "bird's-foot".

Hydrilla

Hydrilla (Esthwaite Waterweed, waterthyme or hydrilla) is a genus of aquatic plant, usually treated as containing just one species, Hydrilla verticillata, though some botanists divide it into several species. It is native to the cool and warm waters of the Old World in Asia, Europe, Africa and Australia, with a sparse, scattered distribution; in Europe, it is reported from Ireland, Great Britain, Germany, and the Baltic States, and in Australia from Northern Territory, Queensland, and New South Wales.^[1][2][3]

The stems grow up to 1–2 m long. The leaves are arranged in whorls of two to eight around the stem, each leaf 5–20 mm long and 0.7–2 mm broad, with serrations or small spines along the leaf margins; the leaf midrib is often reddish when fresh. It is monoecious (sometimes dioecious), with male and female flowers produced separately on a single plant; the flowers are small, with three sepals and three petals, the petals 3–5 mm long, transparent with red streaks. It reproduces primarilyvegetatively by fragmentation and by rhizomes and turions (overwintering), and flowers are rarely seen.^[2][4][5][6] They have air spaces to keep them upright.