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SUMMARY / RELATED TOPICS

Recommended exposure limit

A recommended exposure limit is an occupational exposure limit, recommended by the United States National Institute for Occupational Safety and Health. The REL is a level that NIOSH believes would be protective of worker safety and health over a working lifetime if used in combination with engineering and work practice controls and medical monitoring and labeling of hazards, worker training and personal protective equipment. To formulate these recommendations, NIOSH evaluates all known and available medical, engineering, chemical and other information. Although not enforceable limits, RELS are transmitted to the Occupational Safety and Health Administration or the Mine Safety and Health Administration of the U. S. Department of Labor for use in promulgating legal standards. All RELs are located in the NIOSH Pocket Guide to Chemical Hazards, along with other key data for 677 chemical or substance groupings; the Pocket Guide is a source of general industrial hygiene information for workers and occupational health professionals.

NIOSH recommendations are published in a variety of documents, including: Criteria documents - These recommend workplace exposure limits and appropriate preventive measures to reduce or eliminate adverse health effects and accidental injuries. Current Intelligence Bulletins - These share new scientific information about occupational hazards, highlighting a unrecognized hazard, reporting new data on a known hazard, or presenting information on hazard control. Alerts, Special Hazard Reviews, Occupational Hazard Assessments, Technical Guidelines - These assess the safety and health problems associated with a given agent or hazard and recommend appropriate control and surveillance methods. Although these documents are not intended to supplant the more comprehensive criteria documents, they are prepared to assist OSHA and MSHA in the formulation of regulation. In addition to these publications, NIOSH periodically presents testimony before various Congressional committees and at OSHA and MSHA rulemaking hearings.

NIOSH Pocket Guide to Chemical Hazards

Rank of a group

For the dimension of the Cartan subgroup, see Rank of a Lie groupIn the mathematical subject of group theory, the rank of a group G, denoted rank, can refer to the smallest cardinality of a generating set for G, rank ⁡ = min. If G is a finitely generated group the rank of G is a nonnegative integer; the notion of rank of a group is a group-theoretic analog of the notion of dimension of a vector space. Indeed, for p-groups, the rank of the group P is the dimension of the vector space P/Φ, where Φ is the Frattini subgroup; the rank of a group is often defined in such a way as to ensure subgroups have rank less than or equal to the whole group, automatically the case for dimensions of vector spaces, but not for groups such as affine groups. To distinguish these different definitions, one sometimes calls this rank the subgroup rank. Explicitly, the subgroup rank of a group G is the maximum of the ranks of its subgroups: sr ⁡ = max H ≤ G min. Sometimes the subgroup rank is restricted to abelian subgroups.

For a nontrivial group G, we have rank = 1. The trivial group T has rank = 0. For a free abelian group Z n. If X is a set and G = F is the free group with free basis X rank = |X|. If a group H is a homomorphic image of a group G rank ≤ rank. If G is a finite non-abelian simple group rank = 2; this fact is a consequence of the Classification of finite simple groups. If G is a finitely generated group and Φ ≤ G is the Frattini subgroup of G rank = rank. If G is the fundamental group of a closed connected 3-manifold M rank≤g, where g is the Heegaard genus of M. If H,K ≤ F are finitely generated subgroups of a free group F such that the intersection L = H ∩ K is nontrivial L is finitely generated andrank − 1 ≤ 2; this result is due to Hanna Neumann. The Hanna Neumann conjecture states that in fact one always has rank − 1 ≤; the Hanna Neumann conjecture has been solved by Igor Mineyev and announced independently by Joel Friedman. According to the classic Grushko theorem, rank behaves additively with respect to taking free products, that is, for any groups A and B we haverank = rank + rank.

If G = ⟨ x 1, …, x n | r = 1 ⟩ is a one-relator group such that r is not a primitive element in the free group F, that is, r does not belong to a free basis of F rank = n. There is an algorithmic problem studied in group theory, known as the rank problem; the problem asks, for a particular class of finitely presented groups if there exists an algorithm that, given a finite presentation of a group from the class, computes the rank of that group. The rank problem is one of the harder algorithmic problems studied in group theory and little is known about it. Known results include: The rank problem is algorithmically undecidable for the class of all finitely presented groups. Indeed, by a classical result of Adian–Rabin, there is no algorithm to decide if a finitely presented group is trivial, so the question of whether rank=0 is undecidable for finitely presented groups; the rank problem is decidable for finitely generated abelian groups. The rank problem is decidable for finitely generated nilpotent groups.

The reason is that for such a group G, the Frattini subgroup of G contains the commutator subgroup of G and hence the rank of G is equal to the rank of the abelianization of G. The rank problem is undecidable for word hyperbolic groups; the rank problem is decidable for torsion-free Kleinian groups. The rank problem is open for finitely generated abelian groups, for free groups, for 3-manifold groups; the rank of a finitely generated group G can be equivalently defined as the smallest cardinality of a set X such that there exists an onto homomorphism F → G, where F is the free group with free basis X. There is a dual notion of co-rank of a finitely generated group G defined as the largest cardinality of X such that there exists an onto homomorphism G → F. Unlike rank, co-rank is always algorithmically computable for finitely presented groups, using the algorithm of Makanin and Razborov for solving systems of equations in free groups; the not

Clifton, Derbyshire

Clifton is a village in the Derbyshire Dales district of Derbyshire, England. The village is situated about 1.2 miles south west of Ashbourne, is close to the border with Staffordshire. The appropriate civil parish is called Compton; the population of this civil parish at the 2011 Census was 500. Margery Bower is a round barrow assumed to date from the Bronze age, it lies on the southern side of the village on the road to Snelston. Clifton Hall was built in the late 18th century, altered in the 20th centuries, it stands close to the centre of the village on Chapel Lane at 52.9995°N 1.7533°W / 52.9995. Holy Trinity church was designed by Henry Isaac Stevens of Derby, built in 1845. Opposite the church stands the Cock Inn public house; the village had a railway station, opened in 1852 as Clifton and renamed in 1893 as Clifton, on a branch of the North Staffordshire Railway between Rocester and Ashbourne. Passenger services ended in 1954 with the line closing for freight services in 1964. Education and recreational facilities in and around the village include: Clifton Primary School Clifton recreation ground Clifton Cricket club Ashbourne Golf CourseIn March 2014, the village made worldwide headlines as the first site for the'Speedy Shop', an automated retailing solution for small communities designed and manufactured by local business Villagevending.com.

The shop provides a wide range of supplies to the village using a unique automated machine styled like a traditional village stores, is the brainchild of local entrepreneur Peter Fox and his colleague Dave Russell. At the site of the old corn mill lies a stone which acts as the Down'ards goal in the annual traditional Royal Shrovetide Football match. There are two adjacent stone markers, the old and the new

Chen Mingyuan

Chen Mingyuan is a Chinese scholar who works in various disciplines such as linguistics, informatics, computer sciences, modern poetry. On April 23, 1989, Chen gave a speech at Peking University, expressing his support for the student movements and criticisms of the government; this speech was considered a trigger for the escalation of the student movement in 1989. Chen was born on January 1941, in Shanghai. Chen graduated from Shanghai Middle School in 1958, earned his mathematics degree at ShanghaiTech University in 1963. Chen formed a cross-age friendship in his adolescence with the prominent scholar and poet, Guo Moruo because of their shared interests in poetry writing, he studied Chinese linguistics at Peking University. In 1978, he was assigned a position at the Institute of Acoustics, Chinese Academy of Sciences as an associate researcher. In 1982, Chen became a professor in the department of linguistics in Beijing Language and Culture College, his book The Economic Life of Liberators was considered the best published work on the economic status of such prominent scholars such as Lu Xun, Kang Youwei, Cai Yuanpei.

Chen was accused of being a counterrevolutionary activist during the Cultural Revolution because his poetry style was similar to that of Mao Zedong.{{ Chen wrote a letter to the government explaining himself, Zhou Enlai and Zhu De both agreed that charge could be dismissed if Mao was willing to be lenient. However, Mao refused to comment. Thus, Chen was imprisoned twice during the Cultural Revolution, he was released after the death of Mao. The government rehabilitated Chen in 1978. Chen supported the student protests in 1989; when students became hesitant to continue their protests after mourning the death of Hu Yaobang, Chen encouraged them not to give up, but to continue their actions. On April 23, 1989, Chen gave an emotional speech at the Triangle in Peking University to the students. In his speech, Chen speak out. First of all, Chen criticized the official mouthpieces such as China Central Television which falsely labelled the student protests as being anti-government in nature. Chen argued that the demonstration and the mourning for Hu Yaobang were spontaneous actions and there were no "black hands" behind them.

Thus, Chen described CCTV as the shameless mouthpiece of the government, who had lost their consciences and had lied to the public for decades. Furthermore, Chen argued that social problems such as inflation, profiteering businesses, insufficient educational funds, wealth polarization were caused by the immoral and corrupted officials and their relatives; the government restricted freedom of speech and democracy because officials feared their scandals would be exposed. To conclude, Chen encouraged students to continue their actions such as boycotting classes and participating demonstrations and to refuse comprise with the government. At the end of his speech, he shouted the slogan "give us liberty or give us death" and "long live students" to the protestors. According to Chai Ling's memoir, Chen's speech was "interrupted many times by thunderous applause." During his speech, Chen compared himself to Wen Yiduo, a scholar, assassinated by the Kuomintang secret agencies because of his anti-government speech during the Chinese Civil War in 1946.

As Chen said: “I will be responsible for every word I said, I am not afraid of any possible consequence including death. I am forty-eight years old now, I am luckier than Mr. Wen who had sacrificed his life when he was forty-seven." Chen's speech was recorded and disseminated to all major universities in Beijing and other cities as well. Wang Dan, one prominent student leader, recalled that students' confidence and motivation were restored after hearing Chen's expressive speech. Student leaders such as Liu Gang hoped other prominent scholars would give similar speeches to students, but most scholars rejected the request and thought that Chen was too radical. Fang Lizhi, another famous scholar in Beijing warned Liu against the radicalization of students by speakers and scholars like Chen, or else some unwanted consequences might occur. Chen was arrested after the crackdown on the student protests, was detained in Qincheng Prison, a maximum-security prison in Changping, with other dissenters including Liu Xiaobo and Liu Gang.

According to Liu Gang's memoir, Chen pretended to be mentally ill and declared that all his wrong behaviors had been caused by his uncontrollable madness. Chen was released, but the length of his sentence and the time of his release remain unknown. Guo Moruo's son, Guo Pingying, sued against Chen in 1997 because Chen called himself the co-author of Xin Chao, a collection of modern poems translated and written by Guo Moruo. Three former secretaries of Guo Moruo testified that there was no collaboration between Guo and Chen for this book. Chen lost the case and abandoned his appeal in June 1997. In 2008, Chen criticized a prominent scholar of Chinese linguistics and cultures, Yu Qiuyu by arguing that Yu misused the concepts of culture and civilization to justify his pseudo-proposition that Chinese culture was the only continuous culture in the world in the last 3,000 years. Zhongguohua yuyin jichu 中国话语音基础. Yuyanxue he xiandai kexue 语言学和现代科学. Wangnian jiao: wo yu Guo Moruo, Tian Han de jiaowang 忘年交: 我与郭沫若, 田

Woodford (UK Parliament constituency)

Woodford was a parliamentary constituency in Essex which returned one Member of Parliament to the House of Commons of the Parliament of the United Kingdom from 1945 until it was renamed for the 1964 general election. The constituency's only Member of Parliament for its entire existence was Sir Winston Churchill of the Conservative Party, he represented the Woodford seat during his second tenure as Prime Minister, continued to hold it until he retired aged 89 at the 1964 general election. He was the Father of the House for the last five years of his tenure in the seat. A statue of him was unveiled on Woodford Green in the constituency in 1959. 1945–1955: The Borough of Wanstead and Woodford, the Urban District of Chigwell. 1955–1964: The Borough of Wanstead and Woodford. The constituency's boundaries were subject to a radical change in 1955, when the new Chigwell constituency was created, removing the less urbanised parts of the seat; the new Wanstead and Woodford constituency was subject to minor boundary changes reflecting alterations to the Municipal Borough of Wanstead and Woodford since the last general redistribution of parliamentary seats in 1955.

The pre and post 1964 seats comprised the whole municipal borough, within its 1955 and 1964 boundaries respectively. Leigh Rayment's Historical List of MPs – Constituencies beginning with "W" Notes

Arthur Sheppard

Arthur Sheppard MVO was private secretary to Archbishop Davidson, who served as Archbishop of Canterbury from 1902 to 1928. Sheppard was born in the son of Arthur Sheppard of Bedford, he was educated at Bedford Modern School. On leaving school, Sheppard was apprenticed to the printing trade at the offices of the Bedfordshire Times. Following a journalistic career he became editor of The Eton Chronicle. In 1889 he became private secretary to Dr. Davidson Dean of Windsor, he accompanied Dr. Davidson successively to the sees of Rochester, Winchester and on his appointment as Archbishop of Canterbury, a position he served from 1902 to 1928, he was secretary of the Cathedrals Commission of the Church Assembly and Secretary of the Tribute to Archbishop Davidson in 1928. In his book "Cantaur: The Archbishops in Their Office", Edward Carpenter stated that of all Randall Davidson's secretaries'Arthur Sheppard, who joined his staff in 1899 and retired only in 1923, was pre-eminent'; some of Sheppard's correspondence is held at the London School of Economics.

Arthur Sheppard married Hannah Elizabeth Grice in 1885 in Bedford. Hannah predeceased they had no children, he died on 21 November 1944 in Bedford. How To Become A Private Secretary. Published by T. Fisher Unwin, 1903