title: Allahabad

text: The 1888 session of the Indian National Congress was held in the city, and by the turn of the 20th century, Allahabad was a revolutionary centre. Nityanand Chatterji became a household name when he hurled a bomb at a European club. In Alfred Park in 1931, Chandrashekhar Azad died when surrounded by British police. The Nehru family homes, Anand Bhavan and Swaraj Bhavan, were centres of Indian National Congress activity. During the years before independence, Allahabad was home to thousands of satyagrahis led by Purushottam Das Tandon, Bishambhar Nath Pande, Narayan Dutt Tiwari and others. The first seeds of the Pakistani nation were sown in Allahabad: on 29 December 1930, Allama Muhammad Iqbal's presidential address to the All-India Muslim League proposed a separate Muslim state for the Muslim-majority regions of India.


title: Allahabad

text: Allahabad is known as the City of Prime Ministers because seven out of 15 prime ministers of India since independence have connections to Allahabad (Jawaharlal Nehru, Lal Bahadur Shastri, Indira Gandhi, Rajiv Gandhi, Gulzarilal Nanda, Vishwanath Pratap Singh and Chandra Shekhar). All seven leaders were either born in Allahabad, were alumni of Allahabad University or were elected from an Allahabad constituency.


title: Allahabad

text: Allahabad's elevation is over 90 m (295 ft) above sea level. The old part of the city, at the south of Allahabad Junction Railway Station, consists of neighbourhoods like Chowk, Johnstongunj, Dariyabad, Khuldabad and many more. In the north of the Railway Station, the new city consists of neighbourhoods like Lukergunj, Civil Lines, Georgetown, Tagoretown, Allahpur, Ashok Nagar, Mumfordgunj, Bharadwaj Puram and others which are relatively new and were built during the British rule. Civil Lines is the central business district of the city and is famous for its urban setting, gridiron plan roads and high rise buildings. Built in 1857, it was the largest town-planning project carried out in India before the establishment of New Delhi. Allahabad has many buildings featuring Indo-Islamic and Indo-Saracenic architecture. Although several buildings from the colonial period have been declared "heritage structures", others are deteriorating. Famous landmarks of the city are Allahabad Museum, New Yamuna Bridge, Allahabad University, Triveni Sangam, All Saints Cathedral, Anand Bhavan, Alfred Park etc. The city experiences one of the highest levels of air pollution worldwide, with the 2016 update of the World Health Organization's "Global Urban Ambient Air Pollution Database" finding Allahabad to have the third highest mean concentration of "PM2.5" (<2.5 μm diameter) particulate matter in the ambient air among all the 2972 cities tested (after Zabol and Gwalior).


title: Allahabad

text: The Allahabad Triveni Sangam (place where three rivers meet) is the meeting place of Ganges, the Yamuna and invisible Saraswati River, which according to Hindu legends, wells up from underground. A place of religious importance and the site for historic Prayag Kumbh Mela held every 12 years, over the years it has also been the site of immersion of ashes of several national leaders, including Mahatma Gandhi in 1948.


title: Allahabad

text: The main ghat in Allahabad is Saraswati Ghat, on the banks of Yamuna. Stairs from three sides descend to the green water of the Yamuna. Above it is a park which is always covered with green grass. There are also facilities for boating here. There are also routes to reach Triveni Sangam by boat from here. Apart from this, there are more than 100 raw ghats in Allahabad.


title: Allahabad

text: Allahabad is in the southern part of Uttar Pradesh, at the confluence of the Ganges and Yamuna. The region was known in antiquity first as the Kuru, then as the Vats country. To the southwest is Bundelkhand, to the east and southeast is Baghelkhand, to the north and northeast is Awadh and to the west is the lower doab (of which Allahabad is part). The city is divided by a railway line running east–west. South of the railway is the Old Chowk area, and the British-built Civil Lines is north of it. Allahabad is well placed geographically and culturally. Geographically part of the Ganga-Yamuna Doab (at the mouth of the Yamuna), culturally it is the terminus of the Indian west.


title: Allahabad

text: The Indian Standard Time longitude (25.15°N 82.58°E) is near the city. According to a United Nations Development Programme report, Allahabad is in a "low damage risk" wind and cyclone zone. In common with the rest of the doab, its soil and water are primarily alluvial. Pratapgarh is north of the city, Bhadohi is east, Rewa is south, Chitrakoot (earlier Banda) is west, and Kaushambi, which was until recently a part of Allahabad, is North-West.


title: Allahabad

text: Allahabad has a humid subtropical climate common to cities in the plains of North India, designated "Cwa" in the Köppen climate classification. The annual mean temperature is ; monthly mean temperatures are . Allahabad has three seasons: a hot, dry summer, a cool, dry winter and a hot, humid monsoon. Summer lasts from March to September with daily highs reaching up to 48 °C in the dry summer (from March to May) and up to 40 °C in the hot and extremely humid monsoon season (from June to September). The monsoon begins in June, and lasts until August; high humidity levels prevail well into September. Winter runs from December to February, with temperatures rarely dropping to the freezing point. The daily average maximum temperature is about and the minimum about . Allahabad never receives snow, but, experiences dense winter fog due to numerous wood fires, coal fires, and open burning of rubbish—resulting in substantial traffic and travel delays. Its highest recorded temperature is on 9 June 2019, and its lowest is on 26 December 1961.


title: Allahabad

text: Rain from the Bay of Bengal or the Arabian Sea branches of the southwest monsoon falls on Allahabad from June to September, supplying the city with most of its annual rainfall of . The highest monthly rainfall total, , occurs in August. The city receives 2,961 hours of sunshine per year, with maximum sunlight in May.


title: Allahabad

text: The Ganga-Jamuna Doab, of which Allahabad is a part, is on the western Indus-Gangetic Plain region. The doab (including the Terai) is responsible for the city's unique flora and fauna. Since the arrival of humans, nearly half of the city's vertebrates have become extinct. Others are endangered or have had their range severely reduced. Associated changes in habitat and the introduction of reptiles, snakes and other mammals led to the extinction of bird species, including large birds such as eagles. The Allahabad Museum, one of four national museums in India, is documenting the flora and fauna of the Ganges and the Yamuna.


title: Allahabad

text: To protect the rich aquatic biodiversity of river Ganges from escalating anthropogenic pressures, development of a Turtle sanctuary in Allahabad along with a River Biodiversity Park at Sangam have been approved under Namami Gange programme.


title: Allahabad

text: The most common birds found in the city are doves, peacocks, junglefowl, black partridge, house sparrows, songbirds, blue jays, parakeets, quails, bulbuls, and comb ducks. Large numbers of Deer are found in the Trans Yamuna area of Allahabad. India's first conservation reserve for blackbuck is being created in Allahabad's Meja Forest Division. Other animals in the state include reptiles such as lizards, cobras, kraits, and gharials. During winter, large numbers of Siberian birds are reported in the sangam and nearby wetlands.


title: Allahabad

text: The 2011 census reported a population of 1,112,544 in the area governed by Allahabad Municipal Corporation, corresponding to a density of . In January 2020, the boundaries of Allahabad Municipal Corporation were expanded to ; according to the 2011 census, 1,536,218 people lived within those boundaries; this corresponds to a population density of .


title: Allahabad

text: Natives of Uttar Pradesh form the majority of Allahabad's population. With regards to Houseless Census in Allahabad, total 5,672 families live on footpaths or without any roof cover, this is approximately 0.38% of the total population of Allahabad district. The sex ratio of Allahabad is 901 females per 1000 males and child sex ratio of is 893 girls per 1000 boys, lower than the national average.


title: Allahabad

text: Hindi, the official state language, is the dominant language in Allahabad. Urdu and other languages are spoken by a sizeable minority. Hindus form the majority of Allahabad's population; Muslims compose a large minority. According to provisional results of the 2011 national census, Hinduism is majority religion in Allahabad city with 76.03% followers. Islam is the second most practised religion in the city with approximately 21.94% following it. Christianity is followed by 0.68%, Jainism by 0.10%, Sikhism by 0.28% and Buddhism by 0.28%. Around 0.02% stated 'Other Religion', approximately 0.90% stated 'No Particular Religion'.


title: Allahabad

text: Allahabad's literacy rate at 86.50% is the highest in the region. Male literacy is 90.21% and female literacy 82.17%. For 2001 census same figure stood at 75.81 and 46.38. As per census 2011, total 1,080,808 people are literate in Allahabad of which males and females are 612,257 and 468,551 respectively. Among 35 major Indian cities, Allahabad reported the highest rate of violations of special and local laws to the National Crime Records Bureau.


title: Allahabad

text: Allahabad division, comprising four districts, is headed by the divisional commissioner of Allahabad, who is an Indian Administrative Service (IAS) officer of high seniority, the commissioner is the head of local government institutions (including municipal corporations) in the division, is in charge of infrastructure development in his division, and is also responsible for maintaining law and order in the division. The district magistrate and collector of Allahabad reports to the divisional commissioner. The current commissioner is Ashish Kumar Goel.


title: Allahabad

text: Allahabad district administration is headed by the district magistrate and collector (DM) of Allahabad, who is an IAS officer. The DM is in charge of property records and revenue collection for the central government and oversees the elections held in the district. The DM is also responsible for maintaining law and order in the district. The DM is assisted by a chief development officer; five additional district magistrates for finance/revenue, city, rural administration, land acquisition and civil supply; one chief revenue officer; one city magistrate; and three additional city magistrates. The district has eight tehsils viz. Sadar, Soraon, Phulpur, Handia, Karchhana, Bara, Meja and Kuraon, each headed by a sub-divisional magistrate.


title: Allahabad

text: City comes under the Allahabad Police Zone and Allahabad Police Range, Allahabad Zone is headed by an additional director general-rank Indian Police Service (IPS) officer, and the Allahabad Range is headed inspector general-rank IPS officer. The district police is headed by a senior superintendent of police (SSP), who is an IPS officer, and is assisted by eight superintendents of police or additional superintendents of police for city, either from the IPS or the Provincial Police Service. Each of the several police circles is headed by a circle officer (CO) in the rank of deputy superintendent of police.


title: Allahabad

text: The development of infrastructure in the city is overseen by the Allahabad Development Authority (ADA), which comes under the Department of Housing and Urban Planning of Uttar Pradesh government. The divisional commissioner of Allahabad acts as the "ex-officio" chairperson of ADA, whereas a vice chairperson, a government-appointed IAS officer, looks after the daily matters of the authority. The current chairperson of ADA is Bhanu Chandra Goswami.


title: Allahabad

text: The Allahabad Nagar Nigam, also called Allahabad Municipal Corporation, oversees the city's civic infrastructure. The corporation originated in 1864 as the Municipal Board of Allahabad, when the Lucknow Municipal Act was passed by the Government of India. In 1867, the Civil Lines and the city were amalgamated for municipal purposes. The Cantonment was counted as part of the city in censuses until the 1931 Indian census, when it was started to be counted as a separate census town. The Municipal Board became Allahabad Municipal Corporation in 1959. Allahabad Cantonment has a cantonment board. The city of Allahabad is currently divided into 80 wards, with one member (or corporator) elected from each ward to form the municipal committee. The head of the corporation is the mayor, but, the executive and administration of the corporation are the responsibility of the municipal commissioner, who is an Uttar Pradesh government-appointed Provincial Civil Service officer of high seniority. The current mayor of Allahabad is Abhilasha Gupta, whereas the current municipal commissioner is Avinash Singh.


title: Allahabad

text: Allahabad was declared to have metropolitan status in October 2006. The metropolitan area is referred to in the 2011 Indian census and other official documents as Allahabad Urban Agglomeration. It consists of Allahabad Municipal Corporation, three census towns (the cantonment, Arail Uparhar, and Chak Babura Alimabad), and 17 Outer Growth (OG) areas listed in the table below.


title: Allahabad

text: Allahabad is the seat of Allahabad High Court, the highest judicial body in the state of Uttar Pradesh. The city is known as the "Prime Minister Capital of India", since, seven of fifteen Indian prime ministers have been from the district. Allahabad is administered by several government agencies. As the seat of the Government of Uttar Pradesh, Allahabad is home to local governing agencies and the Uttar Pradesh Legislative Assembly (housed in the Allahabad High Court building). The Allahabad district has two parliamentary constituency, namely, Allahabad and Phul pur and elects 12 members of the legislative assembly (MLAs) to the state legislature.


title: Allahabad

text: Overall Allahabad has a stable and diverse economy comprising various sectors such as State and Central government offices, education and research institutions, real estate, retail, banking, tourism and hospitality, agriculture-based industries, railways, transport and logistics, miscellaneous service sectors, and manufacturing. Average household income of the city is US$2,299.


title: Allahabad

text: The construction sector is a major part of Allahabad's economy. Secondary manufacturers and services may be registered or unregistered; according to the third All India Census for Small Scale Industries, there are more than 10,000 unregistered small-scale industries in the city. An integrated industrial township has been proposed for in Allahabad by the Dedicated Freight Corridor Corporation of India.


title: Allahabad

text: The city is also home to glass and wire-based industry. The main industrial areas of Allahabad are Naini and Phulpur, where several public and private sector companies have offices and factories. Bharat Petroleum Corporation Limited, India's largest oil company (which is state-owned), is constructing a seven-million-tonnes-per-annum (MTPA) capacity refinery in Lohgara with an investment estimated at ₹62 billion. Allahabad Bank, which began operations in 1865, Bharat Pumps & Compressors and A. H. Wheeler and Company have their headquarters in the city. Major companies in the city are Reliance Industries, ITI Limited, BPCL, Dey's Medical, Food Corporation of India, Raymond Synthetics, Triveni Sheet Glass, Triveni Electroplast, EMC Power Ltd, Steel Authority of India, HCL Technologies, Indian Farmers Fertiliser Cooperative (IFFCO), Vibgyor Laboratories, Geep Industries, Hindustan Cable, Indian Oil Corporation Ltd, Baidyanath Ayurved, Hindustan Laboratories.


title: Allahabad

text: The primary economic sectors of the district are tourism, fishing and agriculture, and the city is a hub for India's agricultural industry. In the case of agriculture crops, Paddy has the largest share followed by Bajra, Arhar, Urd and Moong, in declining order during the Kharif season. In Rabi, Wheat is predominantally followed by pulses and oilseed. Among oilseed crops, Mustard has very less area under pure farming and is grown mainly as a mixed crop. Linseed dominates the oilseed scenario of the district and is mainly grown in Jamunapar area. in the case of pulses, gram has the largest area followed by pea and lentil ("masoor"). There is fairly good acreage under barley.


title: Allahabad

text: The main international and domestic airport serving Allahabad is Allahabad Airport , which began operations in February 1966. The airport is from the city centre and lies in Bamrauli, Allahabad. As of now, Allahabad is connected to eleven cities by flight, where Air India's regional arm Alliance Air connects Allahabad to Delhi and Bilaspur, while IndiGo connects it to Bangalore, Mumbai, Kolkata, Raipur, Bhopal, Bhubaneswar and Gorakhpur. The nearest international airports are in Varanasi and Lucknow.


title: Allahabad

text: The world's first airmail flight took place from Allahabad to Naini in February 1911, when 6,000 cards and letters where flown by French pilot Henri Pequet.


title: Allahabad

text: Allahabad Junction is one of the main railway junctions in northern India and headquarters of the North Central Railway Zone.


title: Allahabad

text: The city is connected to most other Uttar Pradesh cities and major Indian cities such as Kolkata, New Delhi, Hyderabad, Patna, Mumbai, Visakhapatnam, Chennai, Bangalore, Guwahati, Thiruvananthapuram, Pune, Bhopal, Kanpur, Lucknow and Jaipur.


title: Allahabad

text: Buses operated by Uttar Pradesh State Road Transport Corporation and Allahabad City Transport Service are an important means of public transport for travelling to various parts of the city, state and outskirts. Auto Rickshaws have been a popular mode of transportation. Cycle rickshaws are the most economical means of transportation in Allahabad along with e-rickshaws.


title: Allahabad

text: Cable-stayed, New Yamuna Bridge (built 2001–04), is in Allahabad and connects the city to the suburb of Naini across the Yamuna. The Old Naini Bridge now accommodates railway and auto traffic. A road bridge across the Ganges also connects Allahabad and Jhusi. National Waterway 1, the longest Waterway in India, connects Allahabad and Haldia.


title: Allahabad

text: The city generates 5,34,760 kg of domestic solid wastes daily, while the per capita generation of waste is 0.40 kg per day. The sewer service areas are divided into nine zones in the city. Allahabad Municipal Corporation oversees the solid waste management project. Allahabad was the first city to get pre-paid meters for electricity bill in Uttar Pradesh. The city is equipped with over 40 CCTVs at major crossings and markets.


title: Allahabad

text: Department of Health and Family Welfare, Government of Uttar Pradesh oversees the healthcare system of Allahabad. Its healthcare system comprises hospitals, medical facilities, private clinics and diagnostic centers. These facilities are either privately owned or owned and facilitated by the government. Allahabad has a total of twenty four hospitals run by the administration. Founded in memory of Pandit Motilal Nehru in 1961, Motilal Nehru Medical College (MLN Medical College and associated hospitals) is a government medical college in Allahabad, with Swaroop Rani Nehru Hospital, Kamla Nehru Memorial Hospital, Sarojini Naidu Children's Hospital and Manohar Das Eye Hospital serving under its affiliation. Some of the known multispecialty hospitals in and around Allahabad are Alka Hospital, Swaroop Rani Nehru Hospital, Amardeep Hospital, Asha Hospital, Ashutosh Hospital and Trauma Centre, Bhola Hospital, Dwarka Hospital, D R S Hospital, Jain Hospital, Parvati Hospital Pvt. Ltd., Phoenix Hospitals Pvt. Ltd., Priya Hospital, Sangam Multispeciality Hospital, Vatsalya Hospital, Yashlok Hospital and Research Centre, etc.


title: Allahabad

text: Allahabad healthcare also comprises many medical research institutes. The city also has diagnostic labs, clinics, consultation providers and pathological institutes like Kriti Scanning Centre, Prayag Scan & Diagnostic Centre, and Sprint Medical.


title: Allahabad

text: IBM selected Allahabad among 16 other global cities for its smart cities programme to help it address challenges like waste management, disaster management, water management and citizen services. The company commenced working on solid waste management and power sector in generating renewable energy.


title: Allahabad

text: A memorandum of understanding was signed on 25 January 2015 between the United States Trade and Development Agency (USTDA) and the Government of Uttar Pradesh for developing Allahabad as a smart city. The pact came into existence after the bilateral meeting between the Indian Prime Minister Narendra Modi and the US President Barack Obama in October 2014, wherein it was announced that the US would assist India in developing three smart cities, Allahabad, Ajmer and Visakhapatnam, in a boost to India's 100 smart city programme. On 27 August 2015 the official list of 98 cities to be developed as smart cities, including Allahabad, was announced by the Government of India. Allahabad Task Force was set up by the Minister of Urban Development Venkaiah Naidu which consists of the divisional commissioner as chairperson, secretaries of housing and urban planning and urban development in Government of Uttar Pradesh, the district magistrate and collector, the vice-chairperson of Allahabad Development Authority and the mayor in addition to the Additional Secretary (Urban Development) in the Ministry of Housing and Urban Affairs and representatives of the Ministry of External Affairs and the USTDA. The project is being assisted by the U.S.-India Business Council.


title: Allahabad

text: As a part of Smart City Project, Civil Lines is being developed on the lines of Lucknow's Hazratganj. A sum of ₹20 crore (US$3,024,000) has been sanctioned to beautify all prominent crossings of the city. As per the plan, the administration proposed uniformity in signage and colour of buildings and a parking lot to be set up to solve traffic congestion. A 1.35 km long riverfront along Yamuna river would be developed by the Allahabad Development Authority, irrigation and power departments at a cost of ₹147.36 crore. The riverfront would be developed in two phases. In the first phase, around 650 metres at Arail would be developed along with the Yamuna, while in the second phase 700 metres of the stretch between New Yamuna Bridge and Boat Club in Kydganj would be taken up.


title: Allahabad

text: The Allahabad educational system is distinct from Uttar Pradesh's other cities, with an emphasis on broad education. Board of High School and Intermediate Education Uttar Pradesh, the world's biggest examining body, is headquartered in the city. Although English is the language of instruction in most private schools, government schools and colleges offer Hindi and English-medium education. Schools in Allahabad follow the 10+2+3 plan. After completing their secondary education, students typically enrol in higher secondary schools affiliated with the Uttar Pradesh Board of High School and Intermediate Education, the ICSE or the CBSE. and focus on liberal arts, business or science. Vocational programs are also available.


title: Allahabad

text: Allahabad attracts students from throughout India. As of 2017, the city has one central university, two State Universities and an open university. Allahabad University, founded in 1876, is the oldest university in the state. Motilal Nehru National Institute of Technology Allahabad is a noted technical institution. Sam Higginbottom University of Agriculture, Technology and Sciences, founded in 1910, as "Agricultural Institute", is an autonomous Christian minority university in Allahabad. Other notable institutions in Allahabad include the Indian Institute of Information Technology – Allahabad; Motilal Nehru Medical College; Ewing Christian College; Harish-Chandra Research Institute; Govind Ballabh Pant Social Science Institute; and Allahabad State University


title: Allahabad

text: Although Hindu women have traditionally worn saris, the shalwar kameez and Western attire are gaining acceptance among younger women. Western dress is worn more by men, although the dhoti and kurta are seen during festivals. The formal male sherwani is often worn with chooridar on festive occasions. Diwali, Holi, Kumbh Mela, Eid al-Fitr and Vijayadasami are the most popular festivals in Allahabad.


title: Allahabad

text: Allahabad has a literary and artistic heritage; the former capital of the United Provinces, it was known as Prayag in the Vedas, the "Ramayana" and the "Mahabharata". Allahabad has been called the "literary capital of Uttar Pradesh", attracting visitors from East Asia; the Chinese travellers Faxian and Xuanzang found a flourishing city in the fifth and seventh centuries, respectively. The number of foreign tourists, which mostly consisted of Asians, visiting the city was 98,167 in 2010 which subsequently increased to 1,07,141 in 2014. The city has a tradition of political graffiti which includes limericks and caricatures. In 1900, "Saraswati", the first Hindi-language monthly magazine in India, was started by Chintamani Ghosh. Mahavir Prasad Dwivedi, the doyen of modern Hindi literature, remained its editors from 1903 to 1920. The Anand Bhavan, built during the 1930s as a new home for the Nehru family when the Swaraj Bhavan became the local Indian National Congress headquarters, has memorabilia from the Gandhi-Nehru family.


title: Allahabad

text: During the 19th and 20th centuries, Hindi literature was modernised by authors such as Mahadevi Varma, Sumitranandan Pant, Suryakant Tripathi 'Nirala' and Harivansh Rai Bachchan. A noted poet was Raghupati Sahay, better known as Firaq Gorakhpuri. Gorakhpuri and Varma have received Jnanpith Awards. Allahabad is a publication centre for Hindi literature, including the Lok Bharti, Rajkamal and Neelabh. Persian and Urdu literature are also studied in the city. Akbar Allahabadi is a noted modern Urdu poet, and Nooh Narwi, Tegh Allahabadi, Shabnam Naqvi and Rashid Allahabadi hail from Allahabad. English author and 1907 Nobel laureate Rudyard Kipling was an assistant editor and overseas correspondent for "The Pioneer".


title: Allahabad

text: Allahabad is noted for historic, cultural and religious tourism. Historic sites include Alfred Park, the Victoria and Thornhill Mayne Memorials, Minto Park, Allahabad Fort, the Ashoka Pillar and Khusro Bagh. Religious attractions include the Kumbh Mela, the Triveni Sangam and All Saints Cathedral. The city hosts the "Maha" Kumbh Mela, the largest religious gathering in the world, every twelve years and the "Ardh" (half) Kumbh Mela every six years. It also hosts a "Magh Mela" annually on the banks of the Triveni Sangam that typically lasts for one and a half months. Cultural attractions include the Allahabad Museum, the Jawahar Planetarium and the University of Allahabad. North Central Zone Culture Centre, under the Ministry of Culture and Prayag Sangeet Samiti are nationally renowned centres of Arts, Dance, Music, local Folk Dance and Music, Plays/Theatre etc. and nurture upcoming artists. The city has also hosted the International Film Festival of Prayag.


title: Allahabad

text: "The Leader" and "The Pioneer" are two major English-language newspapers that are produced and published from the city.


title: Allahabad

text: All India Radio, the national, state-owned radio broadcaster, has AM radio stations in the city. Allahabad has seven FM stations, including two AIR stations: Gyan Vani and Vividh Bharti, four private FM channels: BIG FM 92.7, Red FM 93.5, Fever 104 FM and Radio Tadka and one educational FM radio channel Radio Adan 90.4 run by Allahabad Agricultural Institute. There is a Doordarshan Kendra in the city. Regional TV channels are accessible via cable subscription, direct-broadcast satellite service or Internet-based television.


title: Allahabad

text: Cricket and field hockey are the most popular sports in Allahabad, with kabaddi, kho-kho, gilli danda and pehlwani mostly being played in rural areas near the city. Gully cricket, also known as street cricket, is popular among city youth. The famous cricket club Allahabad Cricketers has produced many national and international cricket players. Several sports complexes are used by amateur and professional athletes; these include the Madan Mohan Malviya Stadium, the Amitabh Bachchan Sports Complex and the Boys' High School and College Gymnasium. There is an international-level swimming complex in Georgetown. The National Sports Academy in Jhalwa trains gymnasts for the Commonwealth Games. The Indira Marathon honours the late prime minister Indira Gandhi.


title: Sleepers

text: Sleepers is a 1996 American legal crime drama film written, produced, and directed by Barry Levinson, and based on Lorenzo Carcaterra's 1995 book of the same name. The film stars Kevin Bacon, Jason Patric, Brad Pitt, Robert De Niro, Dustin Hoffman, Minnie Driver, Vittorio Gassman, Brad Renfro, Ron Eldard, Jeffrey Donovan, Terry Kinney, Joe Perrino, Geoffrey Wigdor, Jonathan Tucker, Bruno Kirby and Billy Crudup. The title is a slang term for juveniles who serve sentences longer than nine months.


title: Sleepers

text: "Sleepers" was theatrically released in the United States on October 18, 1996 and was a box-office hit, grossing $165.6 million against a $44 million budget.


title: Sleepers

text: Lorenzo "Shakes" Carcaterra, Tommy Marcano, Michael Sullivan, and John Reilly are childhood friends living in Hell's Kitchen in the 1960s. Father "Bobby" Carillo, their parish priest and a youth offender himself in the past, tries to teach them right from wrong. They still play pranks and start running small errands for local gangster King Benny.


title: Sleepers

text: In the summer of 1967, the four boys steal a hotdog cart, which they accidentally roll down the subway stairs, severely injuring an elderly man. They are all sentenced to serve time at Wilkinson Home for Boys in Upstate New York; Shakes is given 6 to 12 months, while the others are given 12 to 18 months. During their stay, they are constantly subjected to sexual abuse and torture by head guards Sean Nokes, Henry Addison, Ralph Ferguson and Adam Styler.


title: Sleepers

text: While at the facility, they participate in Wilkinson's annual football game between the guards and inmates. Michael convinces inmate Rizzo Robinson to help win the game. Humiliated, the guards move the boys to solitary confinement for weeks, where they are systematically beaten. Rizzo does not survive and his family is told that he had died of pneumonia.


title: Sleepers

text: In the spring of 1968, shortly before Shakes' release from Wilkinson, he suggests the boys publicly report the abuse. The others refuse, with Michael asserting that no one would believe them or care, and they vow never to speak of it again. The night before Shakes is released, Nokes and the other guards arrange a "farewell party" in which the four boys are again brutally abused to a higher extreme.


title: Sleepers

text: In 1981, John and Tommy, now career criminals, unexpectedly encounter Sean Nokes in a Hell's Kitchen pub. Confronting him, he dismisses the abuse he put them through, and John and Tommy shoot him dead in front of witnesses. Michael, now an assistant district attorney, gets himself assigned to the case; he secretly intends to botch the prosecution and expose what the guards at Wilkinson's did. With Shakes, now a reporter, they form a plan to free John and Tommy and get revenge on the other Wilkinson abusers. With the help of King Benny and Carol, their childhood friend, they carry out their plan using information compiled by Michael on the backgrounds of the guards, helped by Danny Snyder, an alcoholic lawyer, to defend John and Tommy.


title: Sleepers

text: Michael secretly drafts scripted questions in advance, so Snyder casts significant doubt on the testimony of a woman who witnessed the murder, and two other witnesses are intimidated into silence. For Michael's plan to fully succeed, however, he must damage Nokes' reputation and convincingly place John and Tommy at another location at the time of the shooting. Ferguson, when called as a witness, admits that Nokes, like the other guards, used to abuse the boys. To clinch the case, however, a key witness was still needed for John and Tommy's alibi. Shakes has a long talk with Father Bobby, who resists at first, but after learning the truth, reluctantly agrees to perjure himself. At trial, Father Bobby testifies John and Tommy were with him at a New York Knicks game at the time of the shooting and shows three ticket stubs to prove it. As a result, John and Tommy are acquitted.


title: Sleepers

text: The remaining guards are also punished for their crimes: Henry Addison, now a politician who still molests children, is abducted and killed near the local airport by gangsters led by Rizzo's older brother, Eddie "Little Caesar" Robinson, who heard the truth about Rizzo's death from King Benny; Adam Styler, now a corrupt police officer, is imprisoned for taking bribes and murdering a drug dealer; and Ralph Ferguson, a social worker, loses his job and family and is left to live alone with his guilt for the rest of his life.


title: Sleepers

text: Michael, Shakes, John, Tommy, and Carol meet at a local bar to celebrate. It is the last time the four are together. Shakes remains in Hell's Kitchen as a reporter; Michael quits the DA's office, moves to the English countryside, becomes a carpenter and never marries; John and Tommy both die before age 30 – John succumbs to alcohol poisoning due to excessive consumption while Tommy is ambushed and murdered by rival criminals. Carol remains in Hell's Kitchen as a social worker; she has a son, naming him John Thomas Michael Martinez, with the nickname "Shakes".


title: Sleepers

text: The first words spoken in the film are: "This is a true story about friendship that runs deeper than blood". However, the truthfulness and factual accuracy of the film—and the book upon which it is based—were challenged by the Sacred Heart of Jesus Church and School in Manhattan (the school attended by Lorenzo Carcaterra) and by the Manhattan District Attorney's office, among others. Carcaterra has acknowledged that most details in the book were fictionalized, but maintained that the events described in the book actually occurred.


title: Sleepers

text: In its opening weekend the film grossed $12,305,745 in 1,915 theaters in the United States and Canada, debuting atop of the box office. "Sleepers" grossed $53,315,285 domestically and $112,300,000 internationally for a worldwide total of $165,615,285.


title: Sleepers

text: Rotten Tomatoes gives the film an overall approval rating of 73% based on 56 reviews, with an average rating of 6.60/10. The consensus summarizes: "Old friendships are awakened by the need for revenge, making "Sleepers" a haunting nightmare burdened by voiceover yet terrifically captured by Barry Levinson." Review aggregator Metacritic gives it a weighted average score of 49 out of 100 based on 18 critics, indicating "mixed or average reviews".


title: Sleepers

text: Critics praised the performances of De Niro, Hoffman, Bacon, and the young cast, as well as the cinematography and production design. However, multiple critics said the film loses focus in its second half. Owen Gleiberman of "Entertainment Weekly" wrote, “"Sleepers" wants to do something impossible — merge the mournful, drenched-in-shame emotions of child abuse with the huckster gamesmanship of a contraption like "The Sting".”


title: Sleepers

text: David Ansen of "Newsweek" criticized Levinson’s script and reasoned the adult characters of Shakes, Michael, John, and Tommy were not fully fleshed out. Roger Ebert awarded the film three out of four stars, but said it did not engage enough in the moral issues it purported to be about. Steve Davis of "The" "Austin Chronicle" wrote, “What a more interesting film this would have been had Levinson found a way to integrate the past and the present so that one informed the other.”


title: Sleepers

text: When the film was released there was major controversy over how much of the novel had been invented by its author.


title: Sleepers

text: The film was released on VHS by Warner Home Video in 1997. The film was released in DVD on November 3, 2009 and also in Blu-Ray on August 2, 2011.


title: Panzer IV

text: The Panzerkampfwagen" IV (Pz.Kpfw. IV), commonly known as the Panzer" IV, was a German medium tank developed in the late 1930s and used extensively during the Second World War. Its ordnance inventory designation was Sd.Kfz. 161.


title: Panzer IV

text: The Panzer IV was the most numerous German tank and the second-most numerous German fully tracked armoured fighting vehicle of the Second World War; 8,553 Panzer IVs of all versions were built during World War II, only exceeded by the StuG III assault gun with 10,086 vehicles. Its chassis was also used as the base for many other fighting vehicles, including the Sturmgeschütz IV assault gun, the Jagdpanzer IV self-propelled anti-tank gun, the "Wirbelwind" self-propelled anti-aircraft gun, and the "Brummbär" self-propelled gun.


title: Panzer IV

text: The Panzer IV saw service in all combat theatres involving Germany and was the only German tank to remain in continuous production throughout the war. It was originally designed for infantry support, while the similar Panzer III was to fight armoured fighting vehicles. However, as the Germans faced the formidable T-34, the Panzer IV had more development potential, with a larger turret ring to mount more powerful guns, so it swapped roles with the Panzer III whose production wound down in 1943. The Panzer IV received various upgrades and design modifications, intended to counter new threats, extending its service life. Generally, these involved increasing the armour protection or upgrading the weapons, although during the last months of the war, with Germany's pressing need for rapid replacement of losses, design changes also included simplifications to speed up the manufacturing process.


title: Panzer IV

text: The Panzer IV was partially succeeded by the Panther medium tank, which was introduced to counter the Soviet T-34, although it continued to be a significant component of German armoured formations to the end of the war. It was the most widely exported tank in German service, with around 300 sold to Finland, Romania, Spain and Bulgaria. After the war, Syria procured Panzer IVs from France and Czechoslovakia, which saw combat in the 1967 Six-Day War.


title: Panzer IV

text: The Panzer IV was the brainchild of the German general and innovative armoured warfare theorist Heinz Guderian. In concept, it was intended to be a support tank for use against enemy anti-tank guns and fortifications. Ideally, each tank battalion in a panzer division was to have three medium companies of Panzer IIIs and one heavy company of Panzer IVs. On 11 January 1934, the German army wrote the specifications for a "medium tractor", and issued them to a number of defense companies. To support the Panzer III, which would be armed with a anti-tank gun, the new vehicle would have a short-barreled, howitzer-like as its main gun, and was allotted a weight limit of . Development was carried out under the name "Begleitwagen" ("accompanying vehicle"), or BW, to disguise its actual purpose, given that Germany was still theoretically bound by the Treaty of Versailles ban on tanks. MAN, Krupp, and Rheinmetall-Borsig each developed prototypes, with Krupp's being selected for further development.


title: Panzer IV

text: The chassis had originally been designed with a six-wheeled "Schachtellaufwerk" interleaved-roadwheel suspension (as already adopted for German half-tracks), but the German Army amended this to a torsion bar system. Permitting greater vertical deflection of the roadwheels, this was intended to improve performance and crew comfort both on- and off-road. However, due to the urgent requirement for the new tank, neither proposal was adopted, and Krupp instead equipped it with a simple leaf spring double-bogie suspension, with eight rubber-rimmed roadwheels per side.


title: Panzer IV

text: The prototype had a crew of five; the hull contained the engine bay to the rear, with the driver and radio operator, who doubled as the hull machine gunner, seated at the front-left and front-right, respectively. In the turret, the tank commander sat beneath his roof hatch, while the gunner was situated to the left of the gun breech and the loader to the right. The torque shaft ran from the rear engine to the transmission box in the front hull between the driver and radio operator. To keep the shaft clear of the rotary base junction, which provided electrical power to the turret including the motor to turn it, the turret was offset to the left of the chassis center line, and the engine was moved to the right. Due to the asymmetric layout, the right side of the tank contained the bulk of its stowage volume, which was taken up by ready-use ammunition lockers.


title: Panzer IV

text: Accepted into service under the designation "Versuchskraftfahrzeug 622" (Vs.Kfz. 622), "experimental motor vehicle 622", production began in 1936 at "Fried. Krupp Grusonwerk AG" factory at Magdeburg.


title: Panzer IV

text: The first mass-produced version of the Panzer IV was the "Ausführung" A (abbreviated to Ausf. A, meaning "Variant A"), in 1936. It was powered by a Maybach HL108 TR, producing , and used the SGR 75 transmission with five forward gears and one reverse, achieving a maximum road speed of . As main armament, the vehicle mounted the short-barreled, howitzer-like "Kampfwagenkanone" 37 L/24 (7.5 cm KwK 37 L/24) tank gun, which was a low-velocity weapon mainly designed to fire high-explosive shells. Against armoured targets, firing the "Panzergranate" (armour-piercing shell) at the KwK 37 could penetrate , inclined at 30 degrees, at ranges of up to . A MG 34 machine gun was mounted coaxially with the main weapon in the turret, while a second machine gun of the same type was mounted in the front plate of the hull. The main weapon and coaxial machine gun were sighted with a "Turmzielfernrohr" 5b optic while the hull machine gun was sighted with a "Kugelzielfernrohr" 2 optic. The Ausf. A was protected by of steel armour on the front plate of the chassis, and on the turret. This was only capable of stopping artillery fragments, small-arms fire, and light anti-tank projectiles. A total of 35 A versions were produced.


title: Panzer IV

text: In 1937 production moved to the Ausf. B. Improvements included the replacement of the original engine with the more powerful Maybach HL 120TR, and the transmission with the new SSG 75 transmission, with six forward gears and one reverse gear. Despite a weight increase to , this improved the tank's speed to . The glacis plate was augmented to a maximum thickness of , while a new driver's visor was installed on the straightened hull front plate, and the hull-mounted machine gun was replaced by a covered pistol port and visor flap. The superstructure width and ammunition stowage were reduced to save weight. A new commander's cupola was introduced which was adopted from the Panzer III Ausf. C. A Nebelkerzenabwurfvorrichtung (smoke grenade discharger rack) was mounted on the rear of the hull starting in July 1938 and was back fitted to earlier Ausf. A and Ausf. B chassis starting in August 1938. Forty-two Panzer IV Ausf. Bs were manufactured.


title: Panzer IV

text: The Ausf. C replaced the B in 1938. This saw the turret armour increased to , which brought the tank's weight to . After assembling 40 Ausf. Cs, starting with chassis number 80341, the engine was replaced with the improved HL 120TRM. The last of the 140 Ausf. Cs was produced in August 1939.


title: Panzer IV

text: Production changed to the Ausf. D; this variant, of which 248 vehicles were produced, reintroduced the hull machine gun and changed the turret's internal gun mantlet to a thick external mantlet. Again, protection was upgraded, this time by increasing side armour to . As the German invasion of Poland in September 1939 came to an end, it was decided to scale up production of the Panzer IV, which was adopted for general use on 27 September 1939 as the "Sonderkraftfahrzeug" 161 (Sd.Kfz. 161).


title: Panzer IV

text: In response to the difficulty of penetrating the thick armour of British infantry tanks (Matilda and Matilda II) during the Battle of France, the Germans had tested a gun — based on the 5 cm Pak 38 anti-tank gun — on a Panzer IV Ausf. D. However, with the rapid German victory in France, the original order of 80 tanks was cancelled before they entered production.


title: Panzer IV

text: In October 1940, the Ausf. E was introduced. This had of armour on the bow plate, while a appliqué steel plate was added to the glacis as an interim measure. A new driver's visor, adopted from the Sturmgeschütz III was installed on the hull front plate. A new commander's cupola, adopted from the Panzer III Ausf. G, was relocated forward on the turret eliminating the bulge underneath the cupola. Older model Panzer IV tanks were retrofitted with these features when returned to the manufacturer for servicing. 206 Ausf. Es were produced between October 1940 and April 1941.


title: Panzer IV

text: In April 1941, production of the Panzer IV Ausf. F started. It featured single-plate armour on the turret and hull, as opposed to the appliqué armour added to the Ausf. E, and a further increase in side armour to . The main engine exhaust muffler was shortened and a compact auxiliary generator muffler was mounted to its left. The weight of the vehicle was now , which required a corresponding modification of track width from to reduce ground pressure. The wider tracks also facilitated the fitting of track shoe "ice sprags", and the rear idler wheel and front sprocket were modified. The designation Ausf. F was changed in the meantime to Ausf. F1, after the distinct new model, the Ausf. F2, appeared. A total of 471 Ausf. F (later temporarily called F1) tanks were produced from April 1941 to March 1942.


title: Panzer IV

text: On 26 May 1941, mere weeks before Operation Barbarossa, during a conference with Hitler, it was decided to improve the Panzer IV's main armament. Krupp was awarded the contract to integrate again the Pak 38 L/60 gun into the turret. The first prototype was to be delivered by 15 November 1941. Within months, the shock of encountering the Soviet T-34 medium and KV-1 heavy tanks necessitated a new, much more powerful tank gun. In November 1941, the decision to up-gun the Panzer IV to the gun was dropped, and instead Krupp was contracted in a joint development to modify Rheinmetall's pending anti-tank gun design, later known as 7.5 cm Pak 40 L/46.


title: Panzer IV

text: Because the recoil length was too great for the tank's turret, the recoil mechanism and chamber were shortened. This resulted in the KwK 40 L/43. When the new KwK 40 was loaded with the Pzgr. 39 armour-piercing shell, the new gun fired the AP shell at some , a substantial 74% increase over the howitzer-like KwK 37 L/24 gun's muzzle velocity. Initially, the KwK 40 gun was mounted with a single-chamber, ball-shaped muzzle brake, which provided just under 50% of the recoil system's braking ability. Firing the "Panzergranate" 39, the KwK 40 L/43 could penetrate of steel armour at a range of .


title: Panzer IV

text: The longer 7.5 cm guns were a mixed blessing. In spite of the designers' efforts to conserve weight, the new weapon made the vehicle nose-heavy to such an extent that the forward suspension springs were under constant compression. This resulted in the tank tending to sway even when no steering was being applied, an effect compounded by the introduction of the "Ausführung" H in March 1943.


title: Panzer IV

text: The Ausf. F tanks that received the new, longer, KwK 40 L/43 gun were temporarily named Ausf. F2 (with the designation Sd.Kfz. 161/1). The tank increased in weight to . Differences between the Ausf. F1 and the Ausf. F2 were mainly associated with the change in armament, including an altered gun mantlet, internal travel lock for the main weapon, new gun cradle, new "Turmzielfernrohr" 5f optic for the L/43 weapon, modified ammunition stowage, and discontinuing of the "Nebelkerzenabwurfvorrichtung" in favor of turret mounted "Nebelwurfgerät". Three months after beginning production, the Panzer IV Ausf. F2 was renamed Ausf. G.


title: Panzer IV

text: During its production run from March 1942 to June 1943, the Panzer IV Ausf. G went through further modifications, including another armour upgrade which consisted of a face-hardened appliqué steel plate welded (later bolted) to the glacis—in total, frontal armour was now thick. This decision to increase frontal armour was favorably received according to troop reports on 8 November 1942, despite technical problems of the driving system due to added weight. At this point, it was decided that 50% of Panzer IV production would be fitted with thick additional armour plates. On 5 January 1943, Hitler decided that all Panzer IV should have frontal armour. To simplify production, the vision ports on either side of the turret and the loader's forward vision port in the turret front were removed, while a rack for two spare road wheels was installed on the track guard on the left side of the hull. Complementing this, brackets for seven spare track links were added to the glacis plate.


title: Panzer IV

text: For operation in high temperatures, the engine's ventilation was improved by creating slits over the engine deck to the rear of the chassis, and cold weather performance was boosted by adding a device to heat the engine's coolant, as well as a starter fluid injector. A new light replaced the original headlight and the signal port on the turret was removed. On 19 March 1943, the first Panzer IV with "Schürzen" skirts on its sides and turret was exhibited. The double hatch for the commander's cupola was replaced by a single round hatch from very late model Ausf. G. and the cupola was up-armoured from to . In April 1943, the KwK 40 L/43 was replaced by the longer KwK 40 L/48 gun, with a redesigned multi-baffle muzzle brake with improved recoil efficiency. The longer L/48 resulted in the introduction of the Turmzielfernrohr 5f/1 optic.


title: Panzer IV

text: The next version, the Ausf. H, began production in June 1943 and received the designation Sd. Kfz. 161/2. The integrity of the glacis armour was improved by manufacturing it as a single plate. A reinforced final drive with higher gear ratios was introduced. To prevent adhesion of magnetic anti-tank mines, which the Germans feared would be used in large numbers by the Allies, "Zimmerit" paste was added to all the vertical surfaces of the tank's armour. The turret roof was reinforced from to and segments. The vehicle's side and turret were further protected by the addition of hull skirts and turret skirts. This resulted in the elimination of the vision ports located on the hull side, as the skirts obstructed their view. During the Ausf. H's production run, its rubber-tired return rollers were replaced with cast steel, a lighter cast front sprocket and rear idler wheel gradually replaced the previous components, the hull was fitted with triangular supports for the easily damaged side skirts, the Nebelwurfgeraet was discontinued, and a mount in the turret roof, designed for the "Nahverteidigungswaffe", was plugged by a circular armoured plate due to initial production shortages of this weapon.


title: Panzer IV

text: These modifications meant that the tank's weight increased to . In spite of a new six-speed SSG 77 transmission adopted from the Panzer III, top speed dropped to as low as on cross country terrain. An experimental version of the Ausf H was fitted with a hydrostatic transmission but was not put into production.


title: Panzer IV

text: Despite addressing the mobility problems introduced by the previous model, the final production version of the Panzer IV—the Ausf. J—was considered a retrograde from the Ausf. H. Born of necessity, to replace heavy losses, it was greatly simplified to speed production. The electric generator that powered the tank's turret traverse was removed, so the turret had to be rotated manually. The turret traversing mechanism was modified and fitted with a second gear which made hand-operation easier when the vehicle was on sloping terrain. On reasonably level ground, hand operation at 4 seconds to traverse to 12.5° and 29.5 seconds to traverse to 120° was achieved. The resulting space was later used for the installation of an auxiliary fuel tank; road range was thereby increased to , The remaining pistol and vision ports on the turret side hatches were removed, and the engine's radiator housing was simplified by changing the slanted sides to straight sides. Three sockets with screw threads for mounting a 2-ton jib boom crane were welded on the turret roof while the hull roof was thickened from to . In addition, the cylindrical muffler was replaced by two flame-suppressing mufflers. In June 1944 Wa Prüf 6 had decided that because bomb damage at "Panzerfirma Krupp" in Essen had seriously jeopardized tank production, all plates which should have been face-hardened for the Panzer IV were instead made with rolled homogeneous armour plate. By late 1944, "Zimmerit" was no longer being applied to German armoured vehicles, and the Panzer IV's side-skirts had been replaced by wire mesh, while the gunner's forward vision port in the turret front was eliminated and the number of return rollers was reduced from four to three to further speed-up production.


title: Panzer IV

text: In a bid to augment the Panzer IV's firepower, an attempt was made to mate a "Schmalturm" turret — carrying the longer L/70 tank gun from the developing Panther Ausf. F tank design, and partly developed by Rheinmetall from early 1944 onwards — to a Panzer IV hull. This failed and confirmed that the chassis had reached the limit of its adaptability in both weight and available volume.


title: Panzer IV

text: The Panzer IV was originally intended to be used only on a limited scale, so initially Krupp was its sole manufacturer. Prior to the Polish campaign, only 217 Panzer IVs had been produced: 35 Ausf. A; 42 Ausf. B; and 140 Ausf. C; in 1941, production was extended to "Vogtländische Maschinenfabrik" ("VOMAG") (located in the city of Plauen) and the Nibelungenwerk in the Austrian city of St. Valentin.


title: Panzer IV

text: In 1941, an average of 39 tanks per month were built; this rose to 83 in 1942, 252 in 1943, and 300 in 1944. However, in December 1943, Krupp's factory was diverted to manufacture the Sturmgeschütz IV and, in the spring of 1944, the Vomag factory began production of the Jagdpanzer IV, leaving the Nibelungenwerk as the only plant still assembling the Panzer IV. With the slow collapse of German industry under pressure from Allied air and ground offensives—in October 1944 the Nibelungenwerk factory was severely damaged during a bombing raid—by March and April 1945, production had fallen to pre-1942 levels, with only around 55 tanks per month coming off the assembly lines.


title: Panzer IV

text: The Panzer IV was one of the most widely exported German tanks of the Second World War. In 1942, Germany delivered 11 tanks to Romania and 32 to Hungary, many of which were lost on the Eastern Front between the final months of 1942 and the beginning of 1943 during the battles around Stalingrad, at which the Hungarian and Romanian troops there were almost annihilated by the attacking Soviet forces. Romania received approximately 120 Panzer IV tanks of different models throughout the entire war. To arm Bulgaria, Germany supplied 46 or 91 Panzer IVs, and offered Italy 12 tanks to form the nucleus of a new Italian Army armoured division. These were used to train Italian tank crews while the-then Italian leader Benito Mussolini was deposed shortly after the Allied conquest of Sicily but were then retaken by Germany during its occupation of Italy in mid-1943. The Falangist Spanish government petitioned for 100 Panzer IVs in March 1943 but only 20 were ever delivered by December that same year. Finland bought 30 but only received 15 in 1944 and in the same year a second batch of 62 or 72 was sent to Hungary (although 20 of these were subsequently diverted to replace German military losses). The Croatian Ustashe Militia received 10 Ausf. F1 and 5 Ausf. G in the autumn of 1944. In total, 297 Panzer IVs of all models were delivered to Germany's allies.


title: Panzer IV

text: The Panzer IV was the only German tank to remain in both production and combat throughout World War II, and measured over the entire war it comprised 30% of the "Wehrmacht"s total tank strength. Although in service by early 1939, in time for the occupation of Czechoslovakia, at the start of the war the majority of German armour was made up of obsolete Panzer Is and Panzer IIs. The Panzer I in particular had already proved inferior to Soviet tanks, such as the T-26, during the Spanish Civil War.


title: Panzer IV

text: When Germany invaded Poland on 1 September 1939, its armoured corps was composed of 1,445 Panzer Is, 1,223 Panzer IIs, 98 Panzer IIIs and 211 Panzer IVs; the more modern vehicles amounted to less than 10% of Germany's armoured strength. The 1st Panzer Division had a roughly equal balance of types, with 17 Panzer Is, 18 Panzer IIs, 28 Panzer IIIs, and 14 Panzer IVs per battalion. The remaining panzer divisions were heavy with obsolete models, equipped as they were with 34 Panzer Is, 33 Panzer IIs, 5 Panzer IIIs, and 6 Panzer IVs per battalion. Although the Polish Army possessed less than 200 tanks capable of penetrating the German light tanks, Polish anti-tank guns proved more of a threat, reinforcing German faith in the value of the close-support Panzer IV.


title: Panzer IV

text: Despite increased production of the medium Panzer IIIs and IVs prior to the German invasion of France on 10 May 1940, the majority of German tanks were still light types. According to Heinz Guderian, the Wehrmacht invaded France with 523 Panzer Is, 955 Panzer IIs, 349 Panzer IIIs, 278 Panzer IVs, 106 Panzer 35(t)s and 228 Panzer 38(t)s. Through the use of tactical radios and superior tactics, the Germans were able to outmaneuver and defeat French and British armour. However, Panzer IVs armed with the KwK 37 L/24 tank gun found it difficult to engage French tanks such as the Somua S35 and Char B1. The Somua S35 had a maximum armour thickness of , while the KwK 37 L/24 could only penetrate at a range of . The British Matilda II was also heavily armoured, with at least of steel on the front and turret and a minimum of 65 mm on the sides, but were few in number.


title: Panzer IV

text: Although the Panzer IV was deployed to North Africa with the German Afrika Korps, until the longer gun variant began production, the tank was outperformed by the Panzer III with respect to armour penetration. Both the Panzer III and IV had difficulty in penetrating the British Matilda II's thick armour, while the Matilda's 40-mm QF 2 pounder gun could knock out either German tank; the Matilda II's major disadvantage was its low speed. By August 1942, Rommel had only received 27 Panzer IV Ausf. F2s, armed with the L/43 gun, which he deployed to spearhead his armoured offensives. The longer gun could penetrate all American and British tanks in theater at ranges of up to , by that time the most heavily armoured of which was the M3 Grant. Although more of these tanks arrived in North Africa between August and October 1942, their numbers were insignificant compared to the amount of matériel shipped to British forces.


title: Panzer IV

text: With the launching of Operation Barbarossa on 22 June 1941, the unanticipated appearance of the KV-1 and T-34 tanks prompted an upgrade of the Panzer IV's gun to a longer, high-velocity 75 mm gun suitable for anti-tank use. This meant that it could now penetrate the T-34 at ranges of up to at any angle. The 75 mm KwK 40 L/43 gun on the Panzer IV could penetrate a T-34 at a variety of impact angles beyond range and up to . Shipment of the first model to mount the new gun, the Ausf. F2, began in spring 1942, and by the summer offensive there were around 135 Panzer IVs with the L/43 tank gun available. At the time, these were the only German tanks that could defeat T-34 or KV-1 with sheer firepower. They played a crucial role in the events that unfolded between June 1942 and March 1943, and the Panzer IV became the mainstay of the German panzer divisions. Although in service by late September 1942, the Tiger I was not yet numerous enough to make an impact and suffered from serious teething problems, while the Panther was not delivered to German units in the Soviet Union until May 1943. The extent of German reliance on the Panzer IV during this period is reflected by their losses; 502 were destroyed on the Eastern Front in 1942.


title: Panzer IV

text: The Panzer IV continued to play an important role during operations in 1943, including at the Battle of Kursk. Newer types, such as the Panther, were still experiencing crippling reliability problems that restricted their combat efficiency, so much of the effort fell to the 841 Panzer IVs that took part in the battle. Throughout 1943, the German army lost 2,352 Panzer IVs on the Eastern Front; some divisions were reduced to 12–18 tanks by the end of the year. In 1944, a further 2,643 Panzer IVs were destroyed, and such losses were becoming increasingly difficult to replace. Nevertheless, due to a shortage of replacement Panther tanks, the Panzer IV continued to form the core of Germany's armoured divisions, including elite units such as the II SS Panzer Corps, through 1944.


title: Panzer IV

text: In January 1945, 287 Panzer IVs were lost on the Eastern Front. It is estimated that combat against Soviet forces accounted for 6,153 Panzer IVs, or about 75% of all Panzer IV losses during the war.


title: Panzer IV

text: Panzer IVs comprised around half of the available German tank strength on the Western Front prior to the Allied invasion of Normandy on 6 June 1944. Most of the 11 panzer divisions that saw action in Normandy initially contained an armoured regiment of one battalion of Panzer IVs and another of Panthers, for a total of around 160 tanks, although Waffen-SS panzer divisions were generally larger and better equipped than their "Heer" counterparts. Regular upgrades to the Panzer IV had helped to maintain its reputation as a formidable opponent. The bocage countryside in Normandy favored defense, and German tanks and anti-tank guns inflicted very heavy casualties on Allied armour during the Normandy campaign, despite the overwhelming Allied air superiority. German counter-attacks were blunted in the face of Allied artillery, infantry-held anti-tank weapons, tank destroyers and anti-tank guns, as well as the ubiquitous fighter-bomber aircraft. The side skirt armour could predetonate shaped charge anti-tank weapons such as the British PIAT, but could be pulled away by rugged terrain. German tankers in all theaters were "frustrated by the way these skirts were easily torn off when going through dense brush".


title: Panzer IV

text: The Allies had also been improving their tanks; the widely used American-designed M4 Sherman medium tank, while mechanically reliable, repairable, and available in large numbers, suffered from an inadequate gun in terms of armour-piercing. Against earlier-model Panzer IVs, it could hold its own, but with its 75 mm M3 gun, struggled against the late-model Panzer IV. The late-model Panzer IV's frontal hull armour could easily withstand hits from the weapon on the Sherman at normal combat ranges, though the turret remained vulnerable.


title: Panzer IV

text: The British up-gunned the Sherman with their highly effective 76 mm QF 17-pounder anti-tank gun, resulting in the Firefly; although this was the only Allied tank capable of dealing with all current German tanks at normal combat ranges, few (342) were available in time for the Normandy invasion. One Sherman in every British troop of four was a Firefly. By the end of the Normandy campaign, a further 550 Fireflies were built. which was enough to make good any losses. A second British tank equipped with the 17-pdr gun, the Cruiser Mk VIII Challenger, could not participate in the initial landings having to wait for port facilities to be ready to land. It was not until July 1944 that American Shermans fitted with the 76 mm gun M1 gun achieved a parity in firepower with the Panzer IV.


title: Panzer IV

text: By 29 August 1944, as the last surviving German troops of Fifth Panzer Army and Seventh Army began retreating towards Germany, the twin cataclysms of the Falaise Pocket and the Seine crossing cost the Wehrmacht dearly. Of the 2,300 tanks and assault guns it had committed to Normandy (including around 750 Panzer IVs), over 2,200 had been lost. Field Marshal Walter Model reported to Hitler that his panzer divisions had remaining, on average, five or six tanks each.


title: Panzer IV

text: During the winter of 1944–45, the Panzer IV was one of the most numerous tanks in the Ardennes offensive, where further heavy losses—as often due to fuel shortages as to enemy action—impaired major German armoured operations in the West thereafter. The Panzer IVs that took part were survivors of the battles in France between June and September 1944, with around 260 additional Panzer IV Ausf. Js issued as reinforcements.


title: Panzer IV

text: Finland bought 15 new Panzer IV Ausf. Js in 1944 for 5,000,000 Finnish "markkas" each. The remainder of an order for 40 tanks and some StuG IIIs were not delivered and neither were necessary German tank instructors provided. The tanks arrived too late to see action against the Soviet Union but instead ended up being used against Nazi Germany during their withdrawal through Lapland. After the war, they served as training tanks and one portrayed a Soviet KV-1 tank in the movie "The Unknown Soldier" in 1955. The additional weight, going from the 18.4 tons (Ausf. A) to about 25 tons (Ausf. J), of these modifications strained the simple leaf springed suspension. As a result, the Finnish Army often referred to the PzKpfw IV Ausf.J as the "shaker" for its rough ride, when compared to their StuG III's which by comparison had the much better torsion-bar suspension of the PzKpfw III. According to the Finnish this not only affected general crew comfort, but also hampered the accurate aiming of the main gun whilst on the move. What exactly caused these "vibrations" that gave the PzKw IV Ausf. J such a bad name among Finnish tank crews remains somewhat unclear as it isn't mentioned in any German or Allied descriptions, but the inadequate leaf spring suspension and comparison with the very smooth ride of the StuG III seems to be the most likely cause.


title: Panzer IV

text: After 1945, Bulgaria incorporated its surviving Panzer IVs into defensive bunkers as gunpoints on its border with Turkey, along with Soviet T-34 turrets. This defensive line, known as the "Krali Marko Line", remained in use until the fall of communism in 1989.


title: Panzer IV

text: Twenty Panzer IV Ausf. Hs and ten StuG III Ausf. Gs were supplied to Spain in December 1943, a small fraction of what Spain had originally asked for. The Panzer IV represented the best tank in Spanish service between 1944 and 1954, and was deployed along with T-26s and Panzer Is. Spain sold 17 Panzer IVs to Syria in 1967, with the remaining three left conserved. These can be found in Madrid, Burgos and Santovenia de Pisuerga (Valladolid).


title: Panzer IV

text: Most of the tanks Romania had received were lost during combat between 1944 and 1945. These tanks, designated T4 in the army's inventory, were used by the Army's 2nd Armoured Regiment. On 9 May 1945, only two Panzer IVs were left. Romania received another 50 captured Panzer IV tanks from the Red Army after the end of the war. These tanks were of many different models and were in very bad shape—many of them were missing parts and the side-skirts. These German T4 tanks remained in service until 1950, when the Army decided to use only Soviet equipment. By 1954, all German tanks in Romanian military service had been scrapped.


title: Panzer IV

text: While their numbers remain uncertain, Syria received around 60 Panzers that were refurbished in France between 1950 and 1952, followed by 50 others purchased from Czechoslovakia in 1954, per the Czechoslovakia-Syria arms deal. A Soviet 12.7mm DShK machine gun on an anti-aircraft mount was retrofitted on the cupola. These ex-German tanks were used to shell Israeli settlements below the Golan Heights, together with Soviet-supplied T-34s, and were fired upon in 1965 during the Water War by Israeli Super Sherman and Centurion tanks. Syria received 17 Panzer IVs from Spain, with these seeing combat during the Six-Day War in 1967. Panzer IVs also participated in 1973 Yom Kippur War, with some were dug in as pillboxes. Several of Syria's Panzer IVs were captured by the Israeli Army and donated to the Yad La-Shiryon museum. The AAF Tank Museum in Danville, Virginia, later traded a US M5 Stuart light tank to the Latrun museum for one of the Czechoslovak-origin Panzer IVs, which is now an exhibit there.


title: Panzer IV

text: In addition, Turkey was a buyer, with 35 Panzer IVs received until 4 May 1944 in exchange for some chromium ore. Delivery began with the Ausf. G and probably went on with Ausf. H versions. Other sources state only 15 to 22 tanks were delivered in 1943, all of the Ausf G version.


title: Panzer IV

text: The Soviet Army captured significant numbers of German armoured vehicles, including Panzer IVs (its Russian designation was "T-4"). Some of them were pressed into temporary service and some others were used for driver or anti-tank training. Sometimes, captured tanks were used in different temporary units or as single tanks. While captured Tiger I/IIs and Panthers were only permitted to be used until they irrecoverably broke down, the simplicity of the Panzer IV and the large number of captured parts allowed for long-term repair and continued use.


title: Panzer IV

text: At least one captured Panzer IV Ausf. H was used by the Warsaw Tank Brigade of the Polish 2nd Corps in Italy during 1944.


title: Panzer IV

text: The 1st GMR (Groupement Mobile de Reconnaissance) of the FFI (French Forces of the Interior), later called 'Escadron Autonome de Chars Besnier', was equipped in December 1944 with at least one Panzer IV.


title: Panzer IV

text: After that report from the units, the Inspector General of Armored Troops acknowledged this in a report, at 1944.05.06.:


title: Panzer IV

text: In keeping with the wartime German design expediencies of mounting an existing anti-tank gun on a convenient chassis to give mobility, several tank destroyers and infantry support guns were built around the Panzer IV hull. Both the Jagdpanzer IV, initially armed with the L/48 tank gun, the Bunker buster and tank destroyer Dicker Max, armed with a 105mm gun (made in 2 exemplars, both used in the Eastern Front. One caught fire, and the other one fought with success during the Operation Barbarossa and the Operation Blue. During the Operation Blue, it fought in the Battle of Stalingrad) and the Krupp-manufactured Sturmgeschütz IV, which was the casemate of the Sturmgeschütz III mounted on the body of the Panzer IV, proved highly effective in defense. Cheaper and faster to construct than tanks, but with the disadvantage of a very limited gun traverse, around 1,980 Jagdpanzer IVs and 1,140 Sturmgeschütz IVs were produced. Another tank destroyer, the Panzer IV/70, used the same basic 75-millimeter L/70 gun that was mounted on the Panther.


title: Panzer IV

text: Another variant of the Panzer IV was the "Panzerbefehlswagen" IV (Pz. Bef. Wg. IV) command tank. This conversion entailed the installation of additional radio sets with associated mounting racks, transformers, junction boxes, wiring, antennas and an auxiliary electrical generator. To make room for the new equipment, ammunition stowage was reduced from 87 to 72 rounds. The vehicle could coordinate with nearby armour, infantry or even aircraft. Seventeen "Panzerbefehlswagen" were built on Ausf. J chassis in August and September 1944, while another 88 were based on refurbished chassis.


title: Panzer IV

text: The "Panzerbeobachtungswagen" IV (Pz. Beob. Wg. IV) was an artillery observation vehicle built on the Panzer IV chassis. This, too, received new radio equipment and an electrical generator, installed in the left rear corner of the fighting compartment. "Panzerbeobachtungswagens" worked in cooperation with Wespe and Hummel self-propelled artillery batteries.


title: Panzer IV

text: Also based on the Panzer IV chassis was the "Sturmpanzer IV" (called "Brummbär" by Allied intelligence) infantry-support self-propelled gun. These vehicles were primarily issued to four "Sturmpanzer" units (Numbers 216, 217, 218 and 219) and used during the battle of Kursk and in Italy in 1943. Two separate versions of the "Sturmpanzer IV" existed, one without a machine gun in the mantlet and one with a machine gun mounted on the mantlet of the casemate. Furthermore, a artillery gun was mounted in an experimental demountable turret on a Panzer IV chassis. This variant was called the "Heuschrecke" ("grasshopper"). Another 105 mm artillery/anti-tank prototype was the 10.5 cm K (gp.Sfl.) nicknamed "Dicker Max".


title: Panzer IV

text: Four different self-propelled anti-aircraft vehicles were built on the Panzer IV hull. The "Flakpanzer IV "Möbelwagen"" ("moving van") was armed with a anti-aircraft cannon; 240 were built between 1944 and 1945. In late 1944 a new "Flakpanzer", the "Wirbelwind" ("whirlwind"), was designed, with enough armour to protect the gun's crew in a rotating turret, armed with the quadruple 20 mm"Flakvierling" anti-aircraft cannon system; at least 100 were manufactured. Sixty-five (out of an order for 100) similar vehicles with a single 37 mm anti-aircraft cannon were built named "Ostwind" ("East wind"). This vehicle was designed to replace the "Wirbelwind". The final model was the "Flakpanzer IV Kugelblitz", of which only five pilot vehicles were built. This vehicle featured an enclosed turret armed with twin Rheinmetall-Borsig MK 103 aircraft cannon.


title: Panzer IV

text: Although not a direct modification of the Panzer IV, some of its components, in conjunction with parts from the Panzer III, were utilized to make one of the most widely used self-propelled artillery chassis of the war—the "Geschützwagen" III/IV. This chassis was the basis of the "Hummel", of which 666 were built, and also the gun-armed "Nashorn" tank destroyer, with 473 manufactured. To resupply self-propelled howitzers in the field, 150 ammunition carriers were manufactured on the "Geschützwagen" III/IV chassis.


title: Panzer IV

text: Another variant was the "Bergepanzer" IV armoured recovery vehicle. Some were believed to have been converted locally, 21 were converted from hulls returned for repair between October 1944 and January 1945. The conversion involved removing the turret and adding a wooden plank cover with an access hatch over the turret ring and the addition of a 2-ton jib crane and rigid towing bars.


title: Panzer IV

text: Another rare variant was the Panzer IV "mit hydrostatischem antrieb". In 1944, Zahnradfabrik (ZF) Augsburg plant produced a prototype with an unusual drive concept. A Panzer IV Ausf. H tank received a fluid drive instead of the normal gearbox. Two oil pumps were installed behind the engine, which in turn drove two oil engines. An axial engine drive transmitted the power to the rear drive wheels via a reduction gear. Instead of the two steering levers, the driver had a crescent-shaped steering wheel with the steering movements of which two steering cylinders were operated, which in turn regulated the volume of the oil pumps and thus regulated the adjacent force on the two drive wheels. The only prototype built was not used and was shipped to America after the war to be subjected to driving tests. These finally had to be discontinued due to a lack of spare parts. The only surviving vehicle is now in United States Army Ordnance Training and Heritage Center in Maryland.


title: Selenium

text: Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It seldom occurs in its elemental state or as pure ore compounds in the Earth's crust. Selenium – from Greek ( 'Moon') – was discovered in 1817 by , who noted the similarity of the new element to the previously discovered tellurium (named for the Earth).


title: Selenium

text: Selenium is found in , where it partially replaces the sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores, most often during production. Minerals that are pure selenide or selenate compounds are known but rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells. Applications in electronics, once important, have been mostly replaced with silicon semiconductor devices. Selenium is still used in a few types of DC power surge protectors and one type of fluorescent quantum dot.


title: Selenium

text: Although trace amounts of selenium are necessary for cellular function in many animals, including humans, both elemental selenium and (especially) selenium salts are toxic in even small doses, causing selenosis. Selenium is listed as an ingredient in many multivitamins and other dietary supplements, as well as in infant formula, and is a component of the antioxidant enzymes glutathione peroxidase and thioredoxin reductase (which indirectly reduce certain oxidized molecules in animals and some plants) as well as in 3 deiodinase enzymes. Selenium requirements in plants differ by species, with some plants requiring relatively large amounts and others apparently not requiring any.


title: Selenium

text: Selenium forms several allotropes that interconvert with temperature changes, depending somewhat on the rate of temperature change. When prepared in chemical reactions, selenium is usually an amorphous, brick-red powder. When rapidly melted, it forms the black, vitreous form, usually sold commercially as beads. The structure of black selenium is irregular and complex and consists of polymeric rings with up to 1000 atoms per ring. Black Se is a brittle, lustrous solid that is slightly soluble in CS. Upon heating, it softens at 50 °C and converts to gray selenium at 180 °C; the transformation temperature is reduced by presence of halogens and amines.


title: Selenium

text: The red α, β, and γ forms are produced from solutions of black selenium by varying the evaporation rate of the solvent (usually CS). They all have a relatively low, monoclinic crystal symmetry (space group 14) and contain nearly identical puckered Se rings with different arrangements, as in sulfur. The eight atoms of a ring are not equivalent (i.e. they are not mapped one onto another by any symmetry operation), and in fact in the γ-monoclinic form, half the rings are in one configuration (and its mirror image) and half in another. The packing is most dense in the α form. In the Se rings, the Se-Se distance varies depending on where the pair of atoms is in the ring, but the average is 233.5 pm, and the Se-Se-Se angle is on average 105.7° . Other selenium allotropes may contain Se or Se rings.


title: Selenium

text: The most stable and dense form of selenium is gray and has a chiral hexagonal crystal lattice (space group 152 or 154 depending on the chirality) consisting of helical polymeric chains, where the Se-Se distance is 237.3 pm and Se-Se-Se angle is 103.1° . The minimum distance between chains is 343.6 pm. Gray Se is formed by mild heating of other allotropes, by slow cooling of molten Se, or by condensing Se vapor just below the melting point. Whereas other Se forms are insulators, gray Se is a semiconductor showing appreciable photoconductivity. Unlike the other allotropes, it is insoluble in CS. It resists oxidation by air and is not attacked by nonoxidizing acids. With strong reducing agents, it forms polyselenides. Selenium does not exhibit the changes in viscosity that sulfur undergoes when gradually heated.


title: Selenium

text: Owing to its use as a photoconductor in flat-panel x-ray detectors (see below), the optical properties of amorphous selenium (α-Se) thin films have been the subject of intense research.


title: Selenium

text: Selenium has seven naturally occurring isotopes. Five of these, Se, Se, Se, Se, Se, are stable, with Se being the most abundant (49.6% natural abundance). Also naturally occurring is the long-lived primordial radionuclide Se, with a half-life of 9.2×10 years. The non-primordial radioisotope Se also occurs in minute quantities in uranium ores as a product of nuclear fission. Selenium also has numerous unstable synthetic isotopes ranging from Se to Se; the most stable are Se with a half-life of 119.78 days and Se with a half-life of 8.4 days. Isotopes lighter than the stable isotopes primarily undergo beta plus decay to isotopes of arsenic, and isotopes heavier than the stable isotopes undergo beta minus decay to isotopes of bromine, with some minor neutron emission branches in the heaviest known isotopes.


title: Selenium

text: Selenium forms two oxides: selenium dioxide (SeO) and selenium trioxide (SeO). Selenium dioxide is formed by the reaction of elemental selenium with oxygen:


title: Selenium

text: It is a polymeric solid that forms monomeric SeO molecules in the gas phase. It dissolves in water to form selenous acid, HSeO. Selenous acid can also be made directly by oxidizing elemental selenium with nitric acid:


title: Selenium

text: Unlike sulfur, which forms a stable trioxide, selenium trioxide is thermodynamically unstable and decomposes to the dioxide above 185 °C:


title: Selenium

text: Selenium trioxide is produced in the laboratory by the reaction of anhydrous potassium selenate (KSeO) and sulfur trioxide (SO).


title: Selenium

text: Salts of selenous acid are called selenites. These include silver selenite (AgSeO) and sodium selenite (NaSeO).


title: Selenium

text: Selenium disulfide consists of 8-membered rings. It has an approximate composition of SeS, with individual rings varying in composition, such as SeS and SeS. Selenium disulfide has been used in shampoo as an antidandruff agent, an inhibitor in polymer chemistry, a glass dye, and a reducing agent in fireworks.


title: Selenium

text: Selenium trioxide may be synthesized by dehydrating selenic acid, HSeO, which is itself produced by the oxidation of selenium dioxide with hydrogen peroxide:


title: Selenium

text: Iodides of selenium are not well known. The only stable chloride is selenium monochloride (SeCl), which might be better known as selenium(I) chloride; the corresponding bromide is also known. These species are structurally analogous to the corresponding disulfur dichloride. Selenium dichloride is an important reagent in the preparation of selenium compounds (e.g. the preparation of Se). It is prepared by treating selenium with sulfuryl chloride (SOCl). Selenium reacts with fluorine to form selenium hexafluoride:


title: Selenium

text: In comparison with its sulfur counterpart (sulfur hexafluoride), selenium hexafluoride (SeF) is more reactive and is a toxic pulmonary irritant.


title: Selenium

text: Some of the selenium oxyhalides, such as selenium oxyfluoride (SeOF) and selenium oxychloride (SeOCl) have been used as specialty solvents.


title: Selenium

text: Analogous to the behavior of other chalcogens, selenium forms hydrogen selenide, HSe. It is a strongly odiferous, toxic, and colorless gas. It is more acidic than HS. In solution it ionizes to HSe. The selenide dianion Se forms a variety of compounds, including the minerals from which selenium is obtained commercially. Illustrative selenides include mercury selenide (HgSe), lead selenide (PbSe), zinc selenide (ZnSe), and copper indium gallium diselenide (Cu(Ga,In)Se). These materials are semiconductors. With highly electropositive metals, such as aluminium, these selenides are prone to hydrolysis:


title: Selenium

text: Tetraselenium tetranitride, SeN, is an explosive orange compound analogous to tetrasulfur tetranitride (SN). It can be synthesized by the reaction of selenium tetrachloride (SeCl) with .


title: Selenium

text: Selenium, especially in the II oxidation state, forms stable bonds to carbon, which are structurally analogous to the corresponding organosulfur compounds. Especially common are selenides (RSe, analogues of thioethers), diselenides (RSe, analogues of disulfides), and selenols (RSeH, analogues of thiols). Representatives of selenides, diselenides, and selenols include respectively selenomethionine, diphenyldiselenide, and benzeneselenol. The sulfoxide in sulfur chemistry is represented in selenium chemistry by the selenoxides (formula RSe(O)R), which are intermediates in organic synthesis, as illustrated by the selenoxide elimination reaction. Consistent with trends indicated by the double bond rule, selenoketones, R(C=Se)R, and selenaldehydes, R(C=Se)H, are rarely observed.


title: Selenium

text: Selenium (Greek σελήνη "selene" meaning "Moon") was discovered in 1817 by Jöns Jacob Berzelius and Johan Gottlieb Gahn. Both chemists owned a chemistry plant near Gripsholm, Sweden, producing sulfuric acid by the lead chamber process. The pyrite from the Falun Mine created a red precipitate in the lead chambers which was presumed to be an arsenic compound, so the pyrite's use to make acid was discontinued. Berzelius and Gahn wanted to use the pyrite and they also observed that the red precipitate gave off a smell like horseradish when burned. This smell was not typical of arsenic, but a similar odor was known from tellurium compounds. Hence, Berzelius's first letter to Alexander Marcet stated that this was a tellurium compound. However, the lack of tellurium compounds in the Falun Mine minerals eventually led Berzelius to reanalyze the red precipitate, and in 1818 he wrote a second letter to Marcet describing a newly found element similar to sulfur and tellurium. Because of its similarity to tellurium, named for the Earth, Berzelius named the new element after the Moon.


title: Selenium

text: In 1873, Willoughby Smith found that the electrical resistance of grey selenium was dependent on the ambient light. This led to its use as a cell for sensing light. The first commercial products using selenium were developed by Werner Siemens in the mid-1870s. The selenium cell was used in the photophone developed by Alexander Graham Bell in 1879. Selenium transmits an electric current proportional to the amount of light falling on its surface. This phenomenon was used in the design of light meters and similar devices. Selenium's semiconductor properties found numerous other applications in electronics. The development of selenium rectifiers began during the early 1930s, and these replaced copper oxide rectifiers because they were more efficient. These lasted in commercial applications until the 1970s, following which they were replaced with less expensive and even more efficient silicon rectifiers.


title: Selenium

text: Selenium came to medical notice later because of its toxicity to industrial workers. Selenium was also recognized as an important veterinary toxin, which is seen in animals that have eaten high-selenium plants. In 1954, the first hints of specific biological functions of selenium were discovered in microorganisms by biochemist, Jane Pinsent. It was discovered to be essential for mammalian life in 1957. In the 1970s, it was shown to be present in two independent sets of enzymes. This was followed by the discovery of selenocysteine in proteins. During the 1980s, selenocysteine was shown to be encoded by the codon UGA. The recoding mechanism was worked out first in bacteria and then in mammals (see SECIS element).


title: Selenium

text: Native (i.e., elemental) selenium is a rare mineral, which does not usually form good crystals, but, when it does, they are steep rhombohedra or tiny acicular (hair-like) crystals. Isolation of selenium is often complicated by the presence of other compounds and elements.


title: Selenium

text: Selenium occurs naturally in a number of inorganic forms, including selenide, selenate, and selenite, but these minerals are rare. The common mineral selenite is not a selenium mineral, and contains no selenite ion, but is rather a type of gypsum (calcium sulfate hydrate) named like selenium for the moon well before the discovery of selenium. Selenium is most commonly found as an impurity, replacing a small part of the sulfur in sulfide ores of many metals.


title: Selenium

text: In living systems, selenium is found in the amino acids selenomethionine, selenocysteine, and methylselenocysteine. In these compounds, selenium plays a role analogous to that of sulfur. Another naturally occurring organoselenium compound is dimethyl selenide.


title: Selenium

text: Certain soils are selenium-rich, and selenium can be bioconcentrated by some plants. In soils, selenium most often occurs in soluble forms such as selenate (analogous to sulfate), which are leached into rivers very easily by runoff. Ocean water contains significant amounts of selenium.


title: Selenium

text: Typical background concentrations of selenium do not exceed 1 ng/m in the atmosphere; 1 mg/kg in soil and vegetation and 0.5 μg/L in freshwater and seawater.


title: Selenium

text: Selenium is most commonly produced from selenide in many sulfide ores, such as those of copper, nickel, or lead. Electrolytic metal refining is particularly productive of selenium as a byproduct, obtained from the anode mud of copper refineries. Another source was the mud from the lead chambers of sulfuric acid plants, a process that is no longer used. Selenium can be refined from these muds by a number of methods. However, most elemental selenium comes as a byproduct of refining copper or producing sulfuric acid. Since its invention, solvent extraction and electrowinning (SX/EW) production of copper produces an increasing share of the worldwide copper supply. This changes the availability of selenium because only a comparably small part of the selenium in the ore is leached with the copper.


title: Selenium

text: Industrial production of selenium usually involves the extraction of selenium dioxide from residues obtained during the purification of copper. Common production from the residue then begins by oxidation with sodium carbonate to produce selenium dioxide, which is mixed with water and acidified to form selenous acid (oxidation step). Selenous acid is bubbled with sulfur dioxide (reduction step) to give elemental selenium.


title: Selenium

text: About 2,000 tonnes of selenium were produced in 2011 worldwide, mostly in Germany (650 t), Japan (630 t), Belgium (200 t), and Russia (140 t), and the total reserves were estimated at 93,000 tonnes. These data exclude two major producers: the United States and China. A previous sharp increase was observed in 2004 from $4–$5 to $27/lb. The price was relatively stable during 2004–2010 at about US$30 per pound (in 100 pound lots) but increased to $65/lb in 2011. The consumption in 2010 was divided as follows: metallurgy – 30%, glass manufacturing – 30%, agriculture – 10%, chemicals and pigments – 10%, and electronics – 10%. China is the dominant consumer of selenium at 1,500–2,000 tonnes/year.


title: Selenium

text: Researchers found that application of selenium fertilizer to lettuce crops decreased the accumulation of lead and cadmium. Peaches and pears given a foliar selenium spray contained higher levels of selenium and also stayed firm and ripe longer when in storage. In low doses, selenium has shown a beneficial effect on plant resistance to various environmental stress factors including drought, UV-B, soil salinity, and cold or hot temperatures. However, it can damage plants at higher doses.


title: Selenium

text: During the electrowinning of manganese, the addition of selenium dioxide decreases the power necessary to operate the electrolysis cells. China is the largest consumer of selenium dioxide for this purpose. For every tonne of manganese, an average 2 kg selenium oxide is used.


title: Selenium

text: The largest commercial use of Se, accounting for about 50% of consumption, is for the production of glass. Se compounds confer a red color to glass. This color cancels out the green or yellow tints that arise from iron impurities typical for most glass. For this purpose, various selenite and selenate salts are added. For other applications, a red color may be desired, produced by mixtures of CdSe and CdS.


title: Selenium

text: Selenium is used with bismuth in brasses to replace more toxic lead. The regulation of lead in drinking water applications such as in the US with the Safe Drinking Water Act of 1974, made a reduction of lead in brass necessary. The new brass is marketed under the name EnviroBrass. Like lead and sulfur, selenium improves the machinability of steel at concentrations around 0.15%. Selenium produces the same machinability improvement in copper alloys.


title: Selenium

text: The lithium–selenium (Li–Se) battery is one of the most promising systems for energy storage in the family of lithium batteries. The Li–Se battery is an alternative to the lithium–sulfur battery, with an advantage of high electrical conductivity.


title: Selenium

text: Selenium was the basis of the very first solar cells, with the first example of rooftop solar being a selenium cell from 1884. Such cells were later used in battery-free light meters for photography. Copper indium gallium selenide is a material used in solar cells.


title: Selenium

text: Amorphous selenium (α-Se) thin films have found application as photoconductors in flat panel x-ray detectors. These detectors use amorphous selenium to capture and convert incident x-ray photons directly into electric charge.


title: Selenium

text: Small amounts of organoselenium compounds have been used to modify the catalysts used for the vulcanization for the production of rubber.


title: Selenium

text: The demand for selenium by the electronics industry is declining. Its photovoltaic and photoconductive properties are still useful in photocopying, photocells, light meters and solar cells. Its use as a photoconductor in plain-paper copiers once was a leading application, but in the 1980s, the photoconductor application declined (although it was still a large end-use) as more and more copiers switched to organic photoconductors. Though once widely used, selenium rectifiers have mostly been replaced (or are being replaced) by silicon-based devices. The most notable exception is in power DC surge protection, where the superior energy capabilities of selenium suppressors make them more desirable than metal-oxide varistors.


title: Selenium

text: Zinc selenide was the first material for blue LEDs, but gallium nitride dominates that market. Cadmium selenide was an important component in quantum dots. Sheets of amorphous selenium convert X-ray images to patterns of charge in xeroradiography and in solid-state, flat-panel X-ray cameras. Ionized selenium (Se+24) is one of the active mediums used in X-ray lasers.


title: Selenium

text: Selenium is a catalyst in some chemical reactions, but it is not widely used because of issues with toxicity. In X-ray crystallography, incorporation of one or more selenium atoms in place of sulfur helps with multiple-wavelength anomalous dispersion and single wavelength anomalous dispersion phasing.


title: Selenium

text: Selenium is used in the toning of photographic prints, and it is sold as a toner by numerous photographic manufacturers. Selenium intensifies and extends the tonal range of black-and-white photographic images and improves the permanence of prints.


title: Selenium

text: In high concentrations, selenium acts as an environmental contaminant. Sources of pollution include waste materials from certain mining, agricultural, petrochemical, and industrial manufacturing operations. In Belews Lake North Carolina, 19 species of fish were eliminated from the lake due to 150–200 μg Se/L wastewater discharged from 1974 to 1986 from a Duke Energy coal-fired power plant. At the Kesterson National Wildlife Refuge in California, thousands of fish and waterbirds were poisoned by selenium in agricultural irrigation drainage.


title: Selenium

text: Substantial physiological changes may occur in fish with high tissue concentrations of selenium. Fish affected by selenium may experience swelling of the gill lamellae, which impedes oxygen diffusion across the gills and blood flow within the gills. Respiratory capacity is further reduced due to selenium binding to hemoglobin. Other problems include degeneration of liver tissue, swelling around the heart, damaged egg follicles in ovaries, cataracts, and accumulation of fluid in the body cavity and head. Selenium often causes a malformed fish fetus which may have problems feeding or respiring; distortion of the fins or spine is also common. Adult fish may appear healthy despite their inability to produce viable offspring.


title: Selenium

text: Selenium is bioaccumulated in aquatic habitats, which results in higher concentrations in organisms than the surrounding water. Organoselenium compounds can be concentrated over 200,000 times by zooplankton when water concentrations are in the 0.5 to 0.8 μg Se/L range. Inorganic selenium bioaccumulates more readily in phytoplankton than zooplankton. Phytoplankton can concentrate inorganic selenium by a factor of 3000. Further concentration through bioaccumulation occurs along the food chain, as predators consume selenium rich prey. It is recommended that a water concentration of 2 μg Se/L be considered highly hazardous to sensitive fish and aquatic birds. Selenium poisoning can be passed from parents to offspring through the egg, and selenium poisoning may persist for many generations. Reproduction of mallard ducks is impaired at dietary concentrations of 7 μg Se/L. Many benthic invertebrates can tolerate selenium concentrations up to 300 μg/L of Se in their diet.