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Thomas Guide

Thomas Guide is a series of paperback, spiral-bound atlases featuring detailed street maps of various large metropolitan areas in the United States, including Boise, Las Vegas, Los Angeles, Oakland, Phoenix, Portland, Reno-Tahoe, Sacramento, San Francisco, Seattle, Tucson, and Baltimore-Washington metropolitan area. Road Atlas titles are Arizona including Las Vegas, California Including portions of Nevada, and Pacific Northwest covering Washington, Oregon, Western Idaho, Southwestern British Columbia. The map books are usually arranged by county; for example, separate Thomas Guides have been published for Los Angeles County and San Diego County. There are also guides that will have two or three counties combined (for example, Los Angeles and Orange County), or guides that cover a metropolitan area (for instance, the San Francisco Bay Area). Each guide has a detailed index of streets and points of interest, as well as arterial maps for easy page location.

Thomas Guides were a local icon in Southern California for decades, with many companies including the Thomas Guide map grid information for their locations in Yellow Pages listings and other advertisements.

1915: Creation in Oakland, CA
Thomas Bros. Maps, the publishers of the Thomas Guide, previously known as Popular Street Atlas, Street Guide, and Popular Atlas, was started in Oakland, California, in 1915 by cartographer George Coupland Thomas and his two brothers, who were business partners. Early publications were detailed block maps, bird eye view of communities, road & highway maps, and what would be generally referred as generalized tourist maps. Thomas Bros. also produced redlining maps of Los Angeles, Sacramento, San Francisco, San Jose, and the East Bay for the US government-sponsored Home Owners' Loan Corporation in the 1930s.

The company relocated its headquarters to Los Angeles in 1940. The company had grown to publish street maps of cities in several Western states; these maps were sold in fold-out, card stock covers. By the late 1940s, the company had added pocket-sized guidebooks of California and the city of San Francisco which included fold-out maps attached to the inner rear cover. The first street guides, which were initially pocket sized paperback booklets also began to appear at about this time, and were introduced for several counties in California, and one in Washington.

Acquisition by Warren B. Wilson; digital age
After George Coupland Thomas died in 1955, the company was acquired by Coupland Thomas's family lawyer Warren B. Wilson. Wilson's brother Lionel would later become mayor of Oakland.

During the California home development boom of the late 1970s, Wilson moved the company to a newly-built state-of-the-art design building in an industrial park in Irvine, California, in early 1980. For 40 years, Wilson served as CEO and owner of Thomas Bros. Maps (TBM) and was responsible for leading the company into the digital age. Starting in the 1990s, Wilson hired many CEOs to run the company to give him more time for traveling and studying his love of art.

After conversion and completion of all of their pen and ink map atlases to digital format in the mid-1990s, map data became a significant part of TBM company sales. The company had large data contracts in the 1990s with the California Highway Patrol, large utilities, and many area cities and counties. The Thomas Brothers map database had a monopoly in the 1990s, since they had the best street address indexes in them, making them very good for address matching for businesses.

Acquisition by Rand McNally; decline
Because sales of its last produced guidebooks for Washington, D.C., and Virginia did not sell as expected and much money was lost on the website store design, the company was in major debt. The company also intended to conquer the East Coast, but failed to compete against existing mapmakers there. It was purchased by and became a wholly-owned subsidiary of Rand McNally in 1999.

The company made radical changes in operation beginning in November 2003, and let go many of Thomas Brothers' most skilled cartographers and employees. The Rand McNally CEO announced all Irvine data edits would be outsourced to Bangalore, India. The remaining Irvine employees would send and manage the data to and from India and check the map work India editors did before publishing.

After January 2004, many important things in the guides were cut to save money. The valued POI index was no longer updated. Thinner and cheaper paper was used in the map guides. The Irvine source department was closed and no customer corrections were taken or recorded. Many guides were no longer printed yearly. The book name was dropped to just Thomas Guide and colors changed to match Rand McNally colors and product line releases. The popular map store was closed at the Irvine building, which was the last TBM store to close as they had they shut the ones in San Francisco, downtown Los Angeles, and the South Coast Plaza Mall years earlier. The map guides still sell, but the famous digital map database is now outdated. Rand McNally now buys their map data and updates from the big map digital data companies like Tele Atlas and Navteq. They overlay the new streets on their old database for publication.

Rand McNally/TBM no longer has any employees or customer service in California, after laying off the final Irvine headquarters employees in 2009.

An updated Thomas Guide for Los Angeles and Orange Counties was published in 2021, three years after its previous update. Larry Thomas, majority owner of the Thomas Maps brand, noted that California state legislation requires police and fire vehicles to carry Thomas Guides, and that the brand sold 1,000 to 1,500 guides per year.

Technical and technological development
From the early days until the late 1970s, draftsmen, not cartographers, annually compiled and updated maps. Maps were drawn in various scales and sizes. As communities infilled and expanded during the post-war period, this presented problems because the early base maps did not account for the Earth's curvature. Large wall maps were mosaics of smaller units making street alignment interesting. Easter-egg, or deliberate errors, were included on maps to help protect copyrights. These bugs usually were lakes, parks, or other fictitious landmarks; fictitious streets ("trap streets") were avoided due to extensive use by emergency services.

In the growth period of the early 1990s the company led the way and did a lot of new innovative things in the map industry. They were the first map company to start a map education foundation that trained teachers on geography and interesting map lessons and donated map materials to area schools. They were also the first map publishing company to set up a computer map database that could have sections checked out by cartographers, updated, and then checked back in to a live digital map library with date stamps to keep track of what was edited. They also solved many software digital mapping problems that other companies still use today. And they were the first map company to set up a digital map page and grid look-up system for the whole world. Many long-time TBM map book users can still recite what page and grid they live on, even if they stopped using the map books years ago.

Products
Thomas Guide atlases are sometimes referred to as a Thomas Brothers (for Thomas Bros. Maps). However, "Thomas Guides" are so commonly used in Southern California that governments, businesses, individuals and even emergency response agencies will often refer to a "Thomas Guide" page number and map grid to help specify a location.

Businesses often use the large Thomas Guide wall maps. One common use for the wall maps is for delivery businesses, such as a local pizza restaurant. In addition, custom versions of the guides and wall maps are produced for businesses and governments that include such things as census tracts, locations of government facilities, watershed boundaries, and political boundaries.

There are also CD-ROM digital editions of the Thomas Guide atlases available (Microsoft Windows only). In addition, the Thomas Brothers digital database can be licensed to companies and governments to use as a base map for geographical information systems applications.

Updated editions are released annually, although according to interviews with former employees responsible for product updates, actual map content for some titles is updated only every other year. (Product covers are updated every year, even if map content has not changed.) Folding map products are created as a derivative of the Thomas Guides, which carry the Rand McNally name, but mention that the content is from the Thomas Guides. Rand McNally also releases Thomas Guide-like Street Guides and traditional fold-out versions of maps covering regions of North America not covered by the Thomas Guides.

A wide variety of products were produced for sales planning, dispatching, routing, real estate listings and territorial assignments. Besides the regular annual street atlases, they also produced wall maps, Zip Code guides, Rock Products Zones, and Census Tract editions.

Popular Street Atlases (counties):
 * Alameda, CA – first edition 1953
 * Anne Arundel, MD – first edition 1998
 * Baltimore Metropolitan Area, MD – first edition 1999
 * Boise, ID – first edition 2007
 * Central Valley Cities, CA – first edition 1987
 * Clark, NV – first edition 1999
 * Contra Costa, CA – first edition 1953
 * Frederick, MD – first edition 1999
 * Fredericksburg Area, VA – first edition 1999
 * Fresno, CA – first edition 1978
 * Golden Gate (Marin, San Francisco, San Mateo, Santa Clara) – first edition 1961
 * Howard, MD – first edition 1998
 * Kern, CA – first edition 1980
 * King, WA – first edition 1955
 * Kitsap, WA – first edition 2008
 * Los Angeles, CA – first edition 1946
 * Loudoun, VA – first edition 1998
 * Marin, CA – first edition 1953
 * Monterey, CA – first edition 1977
 * Napa-Solano-Yolo, CA – first edition 1981
 * Orange, CA – first edition 1953
 * Phoenix (Maricopa), AZ – first edition 1977
 * Pierce, WA – first edition 1966
 * Portland Metropolitan Area, OR & WA – first edition 1978
 * Prince William, VA – first edition 1998
 * Riverside, CA – first edition 1964
 * Sacramento, CA – first edition 1960
 * Salem, OR – first edition 2008
 * San Bernardino, CA – first edition 1964
 * San Diego, CA – first edition 1951
 * San Francisco, CA – first edition 1953
 * San Mateo, CA – first edition 1953
 * Santa Barbara, CA – first edition 1972
 * Santa Clara, CA – first edition 1953
 * Snohomish, WA – first edition 1956
 * Sonoma, CA – first edition 1953
 * Tucson (Pima), AZ – first edition 2001
 * Ventura, CA – first edition 1965
 * Washington DC Metropolitan Area, DC – first edition 1998

Street Guides (counties):
 * Alameda, CA
 * Contra Costa, CA
 * Los Angeles, CA
 * Marin, CA
 * Orange, CA
 * San Francisco, CA
 * San Mateo, CA
 * Santa Clara, CA

In 2011, it was reported that two hundred copies are stored at the Central Library in downtown Los Angeles, managed by map librarian Glen Creason.

title: Thomas Guide


text:
Windsor Davies

Windsor Davies (28 August 1930 – 17 January 2019) was a British actor. He is best remembered for playing Battery Sergeant Major Williams in the sitcom It Ain't Half Hot Mum (1974–1981) over its entire run. The show's popularity resulted in Davies and his co-star Don Estelle achieving a UK number-one hit with a version of "Whispering Grass" in 1975. He later starred with Donald Sinden in Never the Twain (1981–1991), and his deep Welsh-accented voice was heard extensively in advertising voice-overs.

Early life
Davies was born on 28 August 1930 in Canning Town, East London, to Welsh parents. In 1940 they returned to their native village of Nant-y-moel, Bridgend. Davies studied at Ogmore Grammar School and worked as a coal miner. He performed his National Service in Libya and Egypt, with the East Surrey Regiment, between 1950 and 1952. Following teacher training at Bangor Teacher Training College, he taught English and Maths at Leek in Staffordshire, and at a school in Elephant and Castle, south London.

Davies had become active in amateur dramatics, including the Bromley Little Theatre, and took a short drama course with a Kew theatre company. He became a professional actor at the age of 31 and began working at the Cheltenham repertory theatre in 1961.

Television
Davies' best known role was as Battery Sergeant Major Williams in the British sitcom It Ain't Half Hot Mum (1974–1981), who was modelled on similar individuals Davies had met as a soldier during his national service. "Bastards, real bastards some of them were. They knew it, too, and took pride in it," he once said. Among his character's catchphrases was "Shut Up!!", delivered as an eardrum-shattering military scream. Another phrase was "Oh dear, how sad, never mind", delivered in a dry, ironic manner, and used when others around him had problems. Davies and co-star Don Estelle had a number-one hit in the UK with a semicomic version of "Whispering Grass" in 1975. Journalist Neil Clark, contributing to The Times in 2005, described his performance as the "definitive portrayal of a bullying and uneducated sergeant-major" and reported Spike Milligan was of the opinion that Davies' role was "the funniest comic performance he had ever" watched.

His other television roles included the sailor Taffy in the first of the BBC series The Onedin Line (1971), a boat captain in an episode of Special Branch, a special branch detective in Callan (1972), and the antique dealer Oliver Smallbridge in Never the Twain (1981–1991), with Donald Sinden. In the field of science fiction television, Davies appeared in the 1967 Doctor Who story "The Evil of the Daleks" as Toby; and was the voice of Sergeant Major Zero (a spherical robotic soldier in charge of 100 other spherical robotic soldiers) in the 1983 Gerry Anderson-Christopher Burr production Terrahawks.

He was the subject of This Is Your Life in 1976 when he was surprised by Eamonn Andrews.

In September–October 1985, Davies played the lead role of George Vance, a museum custodian elevated to the peerage, in the six-part BBC Two comedy series The New Statesman. This was based on the play by Douglas Watkinson and is not to be confused with the later sitcom of the same name. (Colin Blakely played the role of Vance in a pilot episode transmitted on BBC2 in December 1984.)

Davies also featured in the BBC comedy sitcom Oh, Doctor Beeching!, written by David Croft and Richard Spendlove, as the Lord Mayor in an episode broadcast in 1997. He also featured in an episode of 2 Point 4 Children in 1999, as Ben's long-lost Uncle Ion.

Films
In the cinema, Davies played major roles in two Carry On films, Behind (1975) and England (1976), in the latter again as a sergeant major. He played Mog in the Welsh rugby film Grand Slam (1978), and was a sergeant in the Highland Regiment in Adolf Hitler: My Part in His Downfall (1973) with Jim Dale and Spike Milligan. In 1989, he revived the role of Sergeant Major Williams in a 30-minute Royal Air Force training film, Hazardous Ops.

Pantomime
Davies appeared as Baron Hardup in the pantomime Cinderella in Bournemouth, UK, from 10 December 1992 to 17 January 1993.

Voice work
Davies' distinctive voice was heard in commercials for New Zealand's Pink Batts house insulations and confectionery ads for Cadbury's Wispa and for Heinz Curried (Baked) Beans. He also appeared alongside New Zealand rugby union coach Alex Wyllie in New Zealand advertisements for Mitre 10 hardware stores in the early 1990s. Davies and Wyllie had worked together previously on the rugby-themed film Old Scores in 1991.

In the 1970s, he read an edition of BBC Radio 4's Morning Story programme, and also narrated the audiobook for the Ladybird children's classic Treasure Island. He sang and voiced many characters in the Paul McCartney film Rupert and the Frog Song in 1984, and appeared in that year's children's film Gabrielle and the Doodleman as three different characters (the Ringmaster, the Black Knight, and an Ugly Sister). In 1984, he auditioned to be the voice of the UK's speaking clock.

Personal life and death
In 1957, he married Eluned Lynne Evans; the couple had four daughters and a son. Eluned died in September 2018. Davies lived in the south of France, and was a keen birdwatcher. Davies was an amateur organist and occasionally played at Capel Y Cymru London.

He died on 17 January 2019, aged 88, four months following the death of his wife. His estate was valued at £883,000.

Filmography

 * The Pot Carriers (1962) - Police Constable
 * Murder Most Foul (1964) - Sergeant Brick
 * The Alphabet Murders (1965) - Dragbot
 * Arabesque (1965) - Policeman in Car Crash (uncredited)
 * The Family Way (1966) - Man in Crowd (uncredited)
 * Drop Dead Darling (1966) - Radio Engineer
 * Assignment K (1968) - Bill (uncredited)
 * Hammerhead (1968) - Police Sergeant
 * Frankenstein Must Be Destroyed (1969) - Police Sergeant
 * The Mind of Mr. J.G. Reeder (1969–1971) - Chief Inspector Pyne
 * Clinic Exclusive (1971) - Geoffrey Carter
 * Endless Night (1972) - Sgt. Keene
 * Adolf Hitler: My Part in His Downfall (1973) - Sgt. MacKay
 * Soft Beds, Hard Battles (1974) - Bisset (uncredited)
 * Mister Quilp (1975) - George
 * Carry On Behind (1975) - Fred Ramsden
 * Confessions of a Driving Instructor (1976) - Mr. Truscott
 * Carry On England (1976) - Sergeant-Major 'Tiger' Bloomer
 * Not Now, Comrade (1976) - Constable Pulford
 * Grand Slam (1978, TV Movie) - Mog Jones
 * The Playbirds (1978) - Assistant Police Commissioner
 * Terrahawks (1983–1986; voice only) - A children's science fiction programme
 * Gabrielle and the Doodleman (1984) - Ringmaster / Black Knight / Ugly Sister
 * Rupert and the Frog Song (1985, Short) - Rupert's Father / Father Frog (voice)
 * Old Scores (1991) - Evan Price
 * The Thief and the Cobbler (1993) - Chief Roofless (voice)
 * The Willows in Winter (1996, TV Movie) - Commissioner of Police (voice)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Windsor Davies


text:
Dunlin

The dunlin (Calidris alpina) is a small wader, formerly sometimes separated with the other "stints" in the genus Erolia. The English name is a dialect form of "dunling", first recorded in 1531–1532. It derives from dun, "dull brown", with the suffix -ling, meaning a person or thing with the given quality.

It is a circumpolar breeder in Arctic or subarctic regions. Birds that breed in northern Europe and Asia are long-distance migrants, wintering south to Africa, southeast Asia and the Middle East. Birds that breed in Alaska and the Canadian Arctic migrate short distances to the Pacific and Atlantic coasts of North America, although those nesting in northern Alaska overwinter in Asia. Many dunlins winter along the Iberian south coast.

Taxonomy
The dunlin was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Tringa alpina. Linnaeus specified the location as Lapland. This species was formerly placed in the genus Erolia, but is now placed with 23 other sandpipers in the genus Calidris that was introduced in 1804 by the German naturalist Blasius Merrem. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific alpina  is from Latin and means "of high mountains", in this case referring to the Alps.

Ten subspecies are recognised:
 * C. a. arctica (Schiøler, 1922) — breeds in northeast Greenland
 * C. a. schinzii (Brehm & Schilling, 1822) — breeds in southeast Greenland, Iceland, the British Isles, Scandinavia & the Baltic
 * C. a. alpina (Linnaeus, 1758) — breeds in northern Europe and northwest Siberia
 * C. a. centralis (Buturlin, 1932) — breeds in north-central and northeast Siberia
 * C. a. sakhalina (Vieillot, 1816) — breeds in eastern Russia to the Chukchi Peninsula
 * C. a. kistchinski Tomkovich, 1986 — breeds around the Sea of Okhotsk to Kuril Islands and Kamchatka
 * C. a. actites Nechaev & Tomkovich, 1988 — breeds on Sakhalin
 * C. a. arcticola (Todd, 1953) — breeds from northwest Alaska to northwest Canada
 * C. a. pacifica (Coues, 1861) — breeds in western and southern Alaska
 * C. a. hudsonia (Todd, 1953) — breeds in central Canada

Description
Measurements:

 * Length: 6.3 - 8.7 in
 * Weight: 1.7 - 2.7 oz
 * Wingspan: 14.2 - 15.0 in

An adult dunlin in breeding plumage shows the distinctive black belly which no other similar-sized wader possesses. The winter dunlin is basically grey above and white below. Juveniles are brown above with two whitish "V" shapes on the back. They usually have black marks on the flanks or belly and show a strong white wingbar in flight. The legs and slightly decurved bill are black. There are a number of subspecies differing mainly in the extent of rufous colouration in the breeding plumage and the bill length. Bill length varies between sexes, the females having longer bills than the males. On the tip of the Dunlin's bill is a soft covering that fills with blood and with many nerve endings, forming a sensitive probe that is used to locate invertebrate prey in mud and sand. Although the bill can look sharp-pointed in dead specimens, in life it is blunt.

The call is a typical sandpiper "peep", and the display song a harsh trill.

Distribution and habitat
Dunlin are small migratory waders, however they show strong philopatry with individuals of the Southern Dunlin (Calidris alpina schinzii) in Sweden and Finland returning to, or very close to, their natal patches. Habitat fragmentation has reduced the availability of habitat patches to these birds through reducing patch size and increasing patch isolation. This reduced connectivity between patches has reduced the movements of Dunlin leaving them more susceptible to inbreeding in these locations.

Behaviour
The dunlin is highly gregarious in winter, sometimes forming large flocks on coastal mudflats or sandy beaches. Large numbers can often be seen swirling in synchronized flight on stop-overs during migration or on their winter habitat.

This bird is one of the most common waders throughout its breeding and wintering ranges, and it is the species with which other waders tend to be compared. At 17 – length and with a 32 – wingspan, it is similar in size to a common starling, but stouter, with a thicker bill.

The dunlin moves along the coastal mudflat beaches it prefers with a characteristic "sewing machine" feeding action, methodically picking small food items. Insects form the main part of the dunlin's diet on the nesting grounds; it eats molluscs, worms and crustaceans in coastal areas.

Breeding
The nest is a shallow scrape on the ground lined with vegetation, into which typically four eggs are laid and incubated by the male and female parents. Chicks are precocial, but are brooded during early development. They start to fly at approximately three weeks of age. The majority of brood care is provided by the male, as the female deserts the brood and often leaves the breeding area.

Apparent hybrids between this species and the white-rumped sandpiper as well as with the purple sandpiper have been reported from the Atlantic coasts of North America and Europe, respectively.

Status
The dunlin has an extremely large range and although the population appears to be decreasing, the population is still very large. The International Union for Conservation of Nature (IUCN) has judged that the threat to the species is of "Least concern". The dunlin is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.

title: Dunlin


text:
Talk:List of chemical engineers

Cindy Crawford
Man, this is a short list. Can anyone verify the urban legend that CIndy Crawford studied chemical engineering?
 * Cindy attended Northwestern University but never graduated.
 * I removed Cindy Crawford's name. Studying one semester as a Chemical Engineer does not make you a chemical engineer. I think only people who should be on this list are chemical engineers and those who have made scientific discoveries related directly to the Chemical Engineering field. As in, discovery of distillation would be a chemistry discovery but design of a process to distill 50,000 barrels a day would be chemical engineering. 24.249.147.3

Other Topics
I don't like the way this page looks. Anyone object to making it a standard bulleted list? Or the name/known for/affiliation table is pretty nice; is there any way to use CSS or XML to make adding entries easy so noobs like me don't have to wrestle with too much markup code like | || etc? BTW, http://sdcc13.ucsd.edu/~aiche/xceleb.html says that Dolph Lundgren has a masters.
 * Agree it could look better but I'm not sure what to do yet. I'm trying to find more ChE's who have contributed a good bit of research to the field. Honestly, it is somewhat difficult as a lot of research, etc. isn't put up in front of the public's eye as much as research in other fields. Who would really want to read about a new way to perform gasification of coal other than someone in that area of research - Reflux 09:00, 25 July 2006 (UTC)

Shouldn't this be a list of individuals that completed a chemical engineering program? I don't think Cindy Crawford and Ashton Kutcher deserve a place here.
 * I agree with this statement. Studing ChE for one semester doesn't make you a Chemical Engineer. I think people who made discoveries related to Chemical Engineer should be on the list though as your degree does not always dictate the work you will be studying/researching. Enviornmental, Chemical, and Petrleum engineering are closely related in their core ideas. Each one then has their own, specific and different area of study but could work in a ChE job position or do research that would directly benefit the chemical engineering field. 24.249.147.3 23:22, 24 July 2006 (UTC)

Exactly... One quarter (or semester) in the chemical engineering major does not make you an engineer.
 * Perhaps they should be moved to something like a "Trivia" section at the bottom of the page?--GregRM 02:29, 24 July 2006 (UTC)
 * I agree 100% that they should not be considered ChE24.249.147.3 23:27, 24 July 2006 (UTC)

 * I started a trivia header to fix the issue. --Sadi Carnot 13:51, 24 July 2007 (UTC)

Doing things that benefit chemical engineering does not make you a chemical engineer, otherwise the list would be filled with mathematicians and scientists. A degree in chemical engineering or membership of AIChE, IChemE etc would qualify in my view. Prior to 1900, we must use reasonable judgement as to people that we would today recognise as chemical engineers and not chemists or mechanical engineers. Wikipedia content must be verifiable. Chemical Engineer 12:21, 30 July 2007 (UTC)

It seems to me that people are adding friends and textbook authors. I don't see that being a university professor or a company director alone is worth adding to the list. If it is, we should have all the heads of chemical engineering departments in the world, and a lot of company CEOs. Writing a textbook is again not exactly unique - if we include all of them, it would add more than a hundred to the list. Quite a few people have written one good specialist text. However, any texts which can be demonstrated to be exceptional in their impact should make the authors notable. Here I would take the originators and not necessarily everyone whom contributes to subsequent editions. Examples of exceptional books would be Perry's Handbook, Coulson & Richardson, Bird, Stewart and Lightfoot. I would not put in Richard Felder just because of his book with Rousseau. I would put him in because it is a verifiable fact that he has won many awards for his contribution to education.Chemical Engineer 12:21, 30 July 2007 (UTC)

Self-poster Daniel Shanefield does not mention chemical engineering in his biography. If he is a chemical engineer, why is he not a member of the AIChE? Chemical Engineer 12:21, 30 July 2007 (UTC)

What is the evidence for Sady Homrich being a chemical engineer? Chemical Engineer 12:21, 30 July 2007 (UTC)

Does anyone know why there were so many entries of people that seem to have little to do with chemical engineering? I removed some, but I think there are more that could be left off as well. Tnxman307 (talk) 20:59, 26 November 2007 (UTC)
 * I think Perl and Steinberger can be dropped. 64.91.216.14 (talk) 23:08, 23 November 2008 (UTC)
 * I concur with the previous post. Both Perl and Steinberger are physicists and won Nobel prizes in that category. Their connection to chemical engineering is rather remote, so I am removing them from the list of notable chemical engineers.ChemE50 (talk) 23:17, 31 March 2010 (UTC)

FYP
FYP is a prominent ChE who has been working in the field for 15 years. He received his Master's degree in Canada, is a prominent member of AIChE, and has been forwarding the field medicine and spearheading new chemical research within Ontario. There seems to be some sort of bias in not including him upon this rather short and dubious list; he's clearly not Cindy Crawford. (talk) 21:21, 17 January 2009 (EST) —Preceding unsigned comment added by 4.253.87.200 (talk)
 * In the remote chance that you are serious, create an article about the person you call FYP (with references by others to the value of his/her work). Linking it to the acronym disambiguation page FYP is not helpful.  See Notability (academics) to see if this person passes the 'professor test'.  Your description could apply to thousands of worthwhile academics who are not in Wikipedia. Chemical Engineer (talk) 16:02, 18 January 2009 (UTC)

Criteria for listing
In my opinion, the criteria for inclusion on or exclusion from this list are unclear. I think many of the comments above support this. It seems to me that some written guidance would be very helpful. Ideally, this list should contain people who have demonstrated skills, knowledge and abilities in the field of chemical engineering. The sentence above the actual list reads, “This is a list of notable chemical engineers, people who studied or practiced chemical engineering.” As of 25 August 2009, the list includes several people who may have enrolled in a chemical engineering program but have either become notable in an unrelated career or have not practiced chemical engineering to any significant degree. A far larger number of individuals who influenced the work of later engineers are not mentioned.ChemE50 (talk) 14:20, 27 August 2009 (UTC)

Here are my suggestions for inclusion: • He/she should have earned an engineering degree and should have practiced in this field for at least five years. • He/she should have made a significant contribution to the field (e.g., patent, peer-reviewed publication, peer citations, professional awards, etc.) ChemE50 (talk) 14:20, 27 August 2009 (UTC)

Proposed additions
In my opinion, the following individuals deserve to be included in this list.ChemE50 (talk) 02:10, 27 August 2009 (UTC)

 * Lawrence B. Evans. CEO of Rive Technology, Inc. Contributed significantly to commercial development of ASPEN process simulation technology. Elected to National Academy of  Engineering  in 2001), “For leadership in the development and application of integrated systems for modeling, simulation, and optimization of industrial chemical processes”.
 * Merrell R. Fenske. (1904 – 1971) Professor of chemical engineering at Pennsylvania State University. Developed the Fenske equation, to calculate the minimum reflux needed to separate two binary components by continuous fractional distillation.
 * Donald Q. Kern. Chemical engineering professor at Case Institute of Technology (now Case Western University). Author of Process Heat Transfer, a major reference for designers of heat transfer equipment. Namesake of the AIChE Donald Q. Kern award.
 * Riki Kobayashi. Professor emeritus of chemical engineering at Rice University. Emeritus member of the National Academy of Engineering, Elected 1995, “… for advances in the knowledge and measurement of the thermodynamic and transport properties of natural gas liquids and gas hydrates”.
 * John J. McKetta. Professor emeritus of chemical engineering at University of Texas. Editor of “Encyclopedia of Chemical Processing and Design.” Emeritus member of the National Academy of Engineering. Elected 1970. Cited for Enlightening experiments on fluid behavior and the director of technical publications.
 * Frank M. Tiller. (1917 – 2006) M. D. Anderson Distinguished Professor at University of Houston. Noted for research in solid-liquid separation and a founder of the American Filtration and Separation Society.
 * A. J. V. Underwood. University College of London. Developed a correlation to estimate the minimum reflux required to produce a specific concentration of a feed component in the distillate from a specified concentration in the feed. The Underwood equation is also known as the Underwood-Fenske equation.
 * F. A. Zenz. Has published extensively on the topic of fluidized particles, including fluidized beds and pneumatic conveying.
 * Yes but the way to do it is to create a page for the individual first, which has references. The above may be true, but they are unsubstantiated until you have the page to refer to. Chemical Engineer (talk) 17:34, 22 October 2009 (UTC)

Proposed deletions
I propose removing the following people from the list of notable chemical engineers, but first I'd like to hear the opinions of other viewers.ChemE50 (talk) 14:20, 27 August 2009 (UTC) Contributions on fields such as fluid dynamics do not apply as Chem Eng.? Jesus!!! von Neumann was a great polymath that contributed to a lot of fields in physics, engineering, mathematics, etc. You are being too narrow minded. --Crio de la Paz (talk) 07:11, 14 December 2011 (UTC)
 * Garry Betty. He earned a chemical engineering degree, but his Wikipedia biography indicates that worked primarily in designing the original personal computer.
 * Frank Capra. He earned a chemical engineering degree in Caltech, but his biography does not indicate that he ever practiced as a chemical engineer.
 * Kevin Greening. He earned a chemical engineering degree, but his biography does not indicate that he ever practiced as a chemical engineer.
 * Pat Kenney. He earned chemical engineering degrees and worked briefly as an engineer, but his biography indicates he is notable only for his career in television.
 * Dolph Lundgren. He earned a chemical engineering degree, but his biography indicates that he never really practiced as a chemical engineer, and is notable only for his career in movies.
 * John von Neumann. He is noted for his work in mathematics and physics, and certainly should be listed as a notable in those fields. His Wikipedia biography does not indicate a direct link to chemical engineering.

 * You could put them at the bottom of the page as is done with List of chemists. Von Neumann qualified in chemical engineering at ETH Zurich.Chemical Engineer (talk) 14:39, 27 August 2009 (UTC)
 * Thanks for your input. I like the idea of separately listing those who became notable for work in other fields. Also, I didn't know that von Neumann had actually studied chemical engineering.ChemE50 (talk) 15:53, 30 August 2009 (UTC)

I quote from the Wikipedia's page:

"Von Neumann made fundamental contributions in exploration of problems in numerical hydrodynamics. For example, with R. D. Richtmyer he developed an algorithm defining artificial viscosity that improved the understanding of shock waves. It is possible that we would not understand much of astrophysics, and might not have highly developed jet and rocket engines without the work of von Neumann.

A problem was that when computers solved hydrodynamic or aerodynamic problems, they tried to put too many computational grid points at regions of sharp discontinuity (shock waves). The mathematics of artificial viscosity smoothed the shock transition without sacrificing basic physics.

Other well known contributions to fluid dynamics included the classic flow solution to blast waves[70], and the co-discovery of the ZND detonation model of explosives.[71]"

"He simultaneously earned a diploma in chemical engineering from the ETH Zurich in Switzerland[1]"

You guys have people whose main achievements are running a company and here you have a fellow that developed concepts in fluid dynamics and the behavior of explosions (ZND Model)... Who is more of a ChemEng to you? I do think you must be out of your mind to think Von Neuman less of a Chem Eng than some of the CEO types you people include as Chem Eng's ... --Crio de la Paz (talk) 04:45, 25 December 2011 (UTC)

Don't add to list
Suggestions and bios should not be put in the list. If the person is notable, create a wiki article. If there is a wiki article, by all means add them.Chemical Engineer (talk) 16:55, 23 March 2010 (UTC)

Suggestions
Please put suggestions here, not on the page. Remove them once there is an article and they can be added.

Maria das Graças Foster Current CEO of Petrobras. First woman to lead an oil company.

Lawrence B. Evans CEO of Rive Technology, Inc. Contributed significantly to commercial development of ASPEN process simulation technology. Elected to National Academy of Engineering in 2001), “For leadership in the development and application of integrated systems for modeling, simulation, and optimization of industrial chemical processes”.The AIChE Lawrence B. Evans Award in Chemical Engineering Practice is named for him.Rive Technology, Inc.

Merrill R. Fenske (1904 – 1971) Professor of chemical engineering. Developed the Fenske equation, to calculate the minimum reflux needed to separate two binary components by continuous distillation. Pennsylvania State University

Rafiqul Gani Professor of chemical engineering at DTU. Director and co-founder of http://www.capec.kt.dtu.dk. Editor-in-chief of [Computers & Chemical Engineering journal|http://www.elsevier.com/wps/find/journaldescription.cws_home/349/description] DTU

Karl Hachmuth Noted for his research into distillation systems; credited with promoting the concept of forming an industry cooperative organization to research behavior of distillation systems. This led to formation of Fractionation Research Inc. Phillips Petroleum Company

Donald Q. Kern Chemical engineering professor at Case Institute of Technology (now Case Western University). Author of Process Heat Transfer, a major reference for designers of heat transfer equipment. Namesake of the AIChE Donald Q. Kern award. Case Western University

Henry Z. Kister Author of books and articles on distillation. Cited by Chemical Engineering magazine for personal achievement in chemical engineering. C. F. Braun (now KBR (Company)), Fluor Corp

Riki Kobayashi Professor emeritus of chemical engineering. Notable for research in phase equilibria and physical properties related to natural gas processing. Elected a member of the National Academy of Engineering in 1995, “... for advances in the knowledge and measurement of the thermodynamic and transport properties of natural gas liquids and gas hydrates”. Rice University

John J. McKetta Professor emeritus of chemical engineering at University of Texas. Editor of “Encyclopedia of Chemical Processing and Design.” Emeritus member of the National Academy of Engineering. Elected 1970 for, "...Enlightening experiments on fluid behavior and the director of technical publications." University of Texas

Ding-Yu Peng Co-discoverer of the Peng-Robinson equation of state. Received 2006 Donald L. Katz Award from Gas Processors Association for accomplishments in gas processing research. University of Saskatchewan

John E. Swearingen (1918 - 2007) Graduated with B. S. in chemical engineering from U. of South Carolina and an M. S. from Carnegie Mellon University. He joined Standard Oil Company of Indiana as a research engineer. In 1960, became CEO of Amoco Corporation

Frank M. Tiller (1917 - 2006) M. D. Anderson Distinguished Professor at University of Houston. Noted for research in solid-liquid separation and a founder of the American Filtration and Separation Society.University of Houston

Haldor Topsoe Founder of Haldor Topsoe Co. Awarded Winthrop-Sears Medal for 2008 by the Chemists' Club of New York.

A. J. V. Underwood Developed a correlation to estimate the minimum reflux required to produce a specific concentration of a feed component in the distillate from a specified concentration in the feed. The Underwood equation is also known as the Underwood-Fenske equation. University College of London

F. A. Zenz Received award from AIChE in 1985 for outstanding chemical engineering contributions. Has published extensively on the topic of fluidized particles, including fluidized beds and pneumatic conveying.

Fictional chemical engineers
The idea of a list of chemical engineers in fiction is great!

 * Reign of Fire is a 2002 film where a chemical engineer is cited by one of main character but I do not know the name.

 * There is a French film where the main character is a chemical engineer maybe someone has watched this film. — Preceding unsigned comment added by 143.54.247.58 (talk) 19:47, 10 August 2011 (UTC)

 * Joseph Fayed, a terrorist who was a chemical engineer in 24, season 4 — Preceding unsigned comment added by Jainsworth16 (talk • contribs) 11:27, 5 April 2012 (UTC)

Surprised you left off The Great Escape - Steve McQueens character, the Cooler King, is a chemical engineer — Preceding unsigned comment added by SeriyaDL (talk • contribs) 08:19, 27 September 2014 (UTC)
 * He is in the list, if you read it.Chemical Engineer (talk) 18:02, 27 September 2014 (UTC)

See Chemical Engineers in Movies. Chemical Engineer (talk) 18:07, 27 September 2014 (UTC)

Avoid "Current"
Saying someone currently has a position will obviously be wrong sooner or later. An encyclopedia should look to the long term, and it is best to write it that way in the beginning. Presumably the fact that they held the position at some time is sufficient. Chemical Engineer (talk) 10:23, 8 October 2018 (UTC)

title: Talk:List of chemical engineers


text:
San Pablo, Laguna

San Pablo, officially the City of San Pablo (Lungsod ng San Pablo), is a 1st class component city in the province of Laguna, Philippines. According to the 2020 census, it has a population of 285,348 people.

It is located in the southern portion of Laguna province, it is one of the oldest cities in the Philippines. By land area, it is the largest in the province of Laguna. Its population ranks sixth within the province after the cities of Calamba, Santa Rosa, Biñan, San Pedro, and Cabuyao.

The city is also known as the "City of Seven Lakes" (Lungsod ng Pitong Lawa), referring to the Seven Lakes of San Pablo: Lake Sampaloc (or Sampalok), Lake Palakpakin, Lake Bunot, Lakes Pandin and Yambo, Lake Muhikap, and Lake Calibato.

San Pablo was part of the Roman Catholic Archdiocese of Lipa since 1910. On November 28, 1967, it became an independent diocese and became the Roman Catholic Diocese of San Pablo.

History
San Pablo's earliest historical record dates back to pre-Spanish times when four large barrios bounded by Mount Makiling composed "Sampalok". In 1571, the first Spanish troops under Captain Juan de Salcedo arrived in the upland village of Sampaloc, which became a parish in 1586, and then a municipality in 1647, and was renamed "San Pablo de Los Montes" in honor of Saint Paul the First Hermit. In 1756, it was placed under the jurisdiction of Batangas province but was returned in 1883 to Laguna.

In 1899, a municipal government was established, with Atty. Innocente Martinez as municipal president. Marcos Paulino was elected municipal president in 1902 when the civil government was set up. From 1926 to 1940, the people of San Pablo worked for its independence from the province of Laguna. On May 7, 1940, the Charter Bill sponsored by Assemblyman Tomas D. Dizon of Laguna's 1st district was approved by President Manuel L. Quezon. The bill became known as the City Charter of San Pablo or Commonwealth Act No. 520 – approved by President Quezon.

The city was inaugurated on March 30, 1941, with Potenciano Malvar, a former governor of Laguna, as the city mayor appointed by president Manuel L. Quezon. Succeeding him in 1941 as an appointed mayor was Manuel Quisumbing, in turn followed by Tomas D. Dizon in 1943 as an appointed mayor. The succeeding mayors were elected after 1955, with Cipriano B. Colago being the first elected city mayor.

Geography
San Pablo has a cool climate owing to its location. It is nestled in the foothills of three mountains: Mount Banahaw, Mount Makiling and the Sierra Madre Mountains. These mountains not only provide attractions for the tourism industry (such as waterfalls) and sources of many forest-based products, but also serve as stewards for the clean air. It is situated 82 km southeast of Manila via Alaminos, 37 km southwest of Santa Cruz via Calauan.

Its soil is suitable for those seeking opportunities in agriculture and horticulture given its richness and fertility. The different barangays have coconut plantation, lanzones fruit – Lansium parasiticum tree plantation and rambutan fruit tree plantation – Rambutan. The place is rich in orchid plants.

Climate
The prevailing climatic conditions in the city is categorized into wet and dry seasons.

Barangays
San Pablo is politically subdivided into 80 barangays. Each barangay consists of puroks and some have sitios.

 * I-A (Sambat)
 * I-B (City+Riverside)
 * I-C (Bagong Bayan)
 * II-A (Triangulo)
 * II-B (Guadalupe)
 * II-C (Unson)
 * II-D (Bulante)
 * II-E (San Anton)
 * II-F (Villa Rey)
 * III-A (Hermanos Belen)
 * III-B
 * III-C (Labak/De Roma)
 * III-D (Villongco)
 * III-E
 * III-F (Balagtas)
 * IV-A
 * IV-B
 * IV-C
 * V-A
 * V-B
 * V-C
 * V-D
 * VI-A (Mavenida)
 * VI-B
 * VI-C (Bagong Pook)
 * VI-D (Lparkers)
 * VI-E (YMCA)
 * VII-A (P.Alcantara)
 * VII-B
 * VII-C
 * VII-D
 * VII-E
 * Atisan
 * Bautista
 * Concepcion (Bunot)
 * Del Remedio (Wawa)
 * Dolores
 * San Antonio 1 (Balanga)
 * San Antonio 2 (Sapa)
 * San Bartolome (Matang-ag)
 * San Buenaventura (Palakpakin)
 * San Crispin (Lumbangan)
 * San Cristobal
 * San Diego (Tiim)
 * San Francisco (Calihan)
 * San Gabriel (Butucan)
 * San Gregorio
 * San Ignacio
 * San Isidro (Balagbag)
 * San Joaquin
 * San Jose (Malamig)
 * San Juan
 * San Lorenzo (Saluyan)
 * San Lucas 1 (Malinaw)
 * San Lucas 2
 * San Marcos (Tikew)
 * San Mateo
 * San Miguel
 * San Nicolas
 * San Pedro
 * San Rafael (Magampon)
 * San Roque (Buluburan)
 * San Vicente
 * Santa Ana
 * Santa Catalina (Sandig)
 * Santa Cruz (Putol)
 * Santa Elena
 * Santa Filomena (Banlagin)
 * Santa Isabel
 * Santa Maria
 * Santa Maria Magdalena (Boe)
 * Santa Monica
 * Santa Veronica (Bae)
 * Santiago I (Bulaho)
 * Santiago II
 * Santisimo Rosario
 * Santo Angel (Ilog)
 * Santo Cristo
 * Santo Niño (Arsum)
 * Soledad (Macopa)

Demographics
According to the 2010 census, San Pablo had a population of 248,890 people, up from 237,259 people and 44,166 households in the 2007 census. The city was once the largest city in Laguna, but it was overtaken by Calamba in the 1990 census. San Pedro followed suit in 1995, then came Santa Rosa and Biñan in 2007, and Cabuyao in 2015, all owing their growth to its proximity to Metro Manila.

Ethnicity and language
The language spoken in the city and the medium of instruction in schools are English and Filipino, also known as Tagalog in this area.

Economy
At the end of the 20th century and the start of the 21st century, economic development shifted from San Pablo to western Laguna. San Pedro, Biñan, Santa Rosa, Cabuyao, Calamba, Los Baños, and Santa Cruz experienced rapid economic development brought about by local and foreign investments, the rapid growth of industrial estates and export processing zones, and the placement of major institutions in those areas, San Pablo City was left behind and remained a semi-developed residential community.

Despite the fact that the city was partly touched by economic development, San Pablo City boasts itself as a potential eco-tourism destination in the province. However, given its human and land resources, various BPO companies are seriously looking at developing the city into the ICT hub of Southern Luzon. Although there were previous attempts to build a similar establishment, SM Prime Holdings was given its go signal in July 2008 to push ahead for SM City San Pablo located at Riverina Commercial Estates along Maharlika Highway at Barangay San Rafael.

Apart from this, the development of the Hacienda Escudero plantation resort town and nearby real estates, which is a joint venture with Landco, is by far the largest planned community investment in the city covering 415 ha: It will include resort type communities; the original Villa Escudero Plantations as the center-piece; commercial establishments like a mall, hotels, and a convention center to be built relative to the distinctive architecture theme of the original Villa Escudero. As such Hacienda Escudero will become the ultimate history town themed community in this part of the country.

ABS-CBN TV-46 San Pablo (DWLY-TV) served the city through its office along Rizal Avenue at the heart of the city until the Duterte government, shut down the operations of the broadcaster and revoked its franchise.

San Pablo also claims the title "City of Buko Pie", although other neighboring towns are also known for producing the delicacy. Colettes' Buko Pie, based in San Pablo, was known for experimenting with different variants of the delicacy. Colette's has also regularly produced the "World's Largest Buko Pie" during San Pablo's Coco Festival. Colette's is the largest Buko Pie brand in the Laguna area with 34 stores. The supply of coconut in San Pablo makes it an ideal spot for putting up buko pie shops.

Franklin Baker Company, one of the well-known companies with operations in San Pablo, has announced that its plant in the city would cease its operations and transfer to another existing facility, owned by the said company, in Davao del Sur by December 2008. The said decision could affect the jobs of at least 1,200 people, the majority of them San Pableños. Various factors are blamed for this closure, including the conversion of big coconut farms into residential areas. However, production was restored in the first quarter of 2009 in the San Pablo plant of Franklin Baker Company due to processing problems encountered at Davao del Sur.

Tourism and recreation
The Seven Lakes of San Pablo, seven crater lakes scattered around the city, have for many generations provided food and livelihood, leisure and respite for the citizens of the city. A bustling city of trade and commerce, it is also a center of education and learning with schools, colleges, and training institutions.

 * Lake Sampaloc, located behind the City Hall, is the youngest crater lake in the San Pablo volcanic field and the largest of the city's seven lakes – Seven Lakes of San Pablo.
 * Lake Bunot (Coconut husk Lake)
 * Lake Calibato
 * Twin Lakes – Lakes Pandin and Yambo
 * Lake Palakpakin
 * Lake Muhikap

Hacienda Escudero Plantation Resort Town is the largest planned community investment in the city covering 415 ha. The resort has the richness of coconut plantation, and provides serenading Filipino songs and Bayanihan Dances (Folk Dances).

Public Playground and Sampalok Lake (Katuparan ng Pangarap: Fulfillment of Dreams) is a public playground in the city built during the term of mayor Atty. Zacarias Africa Ticzon, who as well improved tourism places around Lake Sampaloc, that is near the municipal City Hall. Both places serve as haven for sports, and recreation. The vicinity for tourism consequently encouraged small businesses for restaurants of native dishes catering visitors of the area. It has dramatically contributed income for the city.

The Komikero Komiks Museum, a brick-and-mortar museum meant to showcase the Philippines' rich history of graphic novels and comic books, and the talent of eminent artists in the field, features original art from Philippine comic book industry leaders including Alfredo Alcala, Francisco Coching, Alex Niño, Steve Gan, Nestor Redondo, Tony Velasquez, Hal Santiago, and Gerry Alanguilan. Alanguilan himself curated the museum until his death in 2019.

Healthcare
Most of the large hospitals in San Pablo are located in the city proper, but there are also health centers built for each barangay in San Pablo. Notable hospitals and medical centers are shown below. -Community General Hospital of San Pablo City (C. Colago Ave.) – San Pablo Colleges Medical Center (Barangay San Rafael) – San Pablo City Doctors' Hospital (A. Mabini Street) – Laguna Provincial Hospital San Pablo (Gen. Luna St.)

Transportation
San Pablo city is along the Maharlika Highway which leads to Quezon province. Jeepneys connect San Pablo city proper with nearby Calauan and Rizal, as well as other cities like Tanauan, Santo Tomas, and Calamba. It is also served by vans heading to the cities of Lipa and Santa Rosa.

Philippine National Railways has a station for its southern main line near the city proper.

Utilities
San Pablo's water source is run by its own San Pablo City Water District and is assisted by NAWASA. Just like every other place in Southern Tagalog, San Pablo's electricity is run by Meralco.

Telecommunications
Citizens of San Pablo mainly use PLDT (including Smart), Globe, and Dito Telecommunity, although some may use other internet service providers. Texting stations are often found in retail stores, stands, and residential houses.

Notable personalities

 * Vicente Belen Amante, politician.
 * Cynthia Barker, English politician and former mayor of Hertsmere, England
 * Alexander Gesmundo, 27th Chief Justice of the Supreme Court of the Philippines
 * Arturo Brion, 161th Associate Justice of the Supreme Court
 * Liza Maza, former Gabriela Partylist and Bayan Muna Partylist Representative
 * Celso Al. Carunungan, writer, novelist, and film scriptwriter
 * Gerry Alanguilan, a.k.a. "Komikero," comic book artist and writer best known for his graphic novels Wasted and Elmer
 * Bayani Casimiro, tap dancer
 * Edgar Calabia Samar, poet and fictionist
 * Jay Arcilla, actor and StarStruck Avenger in the 5th season of StarStruck
 * Jiggy Manicad, television news producer/reporter and newscaster
 * Sol Aragones, former news anchor reporter of ABS-CBN; politician
 * Roberta Angela Tamondong, model, beauty pageant titleholder, Miss Eco Teen International 2020, and Binibining Pilipinas Grand International 2022
 * Flor Ramos Contemplacion, Filipina domestic helper executed in Singapore after being convicted of murder.

title: San Pablo, Laguna


text:
Latrodectus

Latrodectus is a broadly distributed genus of spiders with several species that are commonly known as the true widows. This group is composed of those often loosely called black widow spiders, brown widow spiders, and similar spiders. However, the diversity of species is much greater. A member of the family Theridiidae, this genus contains 34 species, which include several North American "black widows" (southern black widow Latrodectus mactans, western black widow Latrodectus hesperus, and northern black widow Latrodectus variolus). Besides these, North America also has the red widow Latrodectus bishopi and the brown widow Latrodectus geometricus, which, in addition to North America, has a much wider geographic distribution. Elsewhere, others include the European black widow (Latrodectus tredecimguttatus), the Australian redback spider (Latrodectus hasseltii) and the closely related New Zealand katipō (Latrodectus katipo), several different species in Southern Africa that can be called button spiders, and the South American black-widow spiders (Latrodectus corallinus and Latrodectus curacaviensis). Species vary widely in size. In most cases, the females are dark-coloured and can be readily identified by reddish markings on the central underside (ventral) abdomen, which are often hourglass-shaped.

These small spiders have an unusually potent venom containing the neurotoxin latrotoxin, which causes the condition latrodectism, both named after the genus. Female widow spiders have unusually large venom glands, and their bite can be particularly harmful to large vertebrates, including humans. However, despite their notoriety, Latrodectus bites rarely cause death or produce serious complications. Only the bites of the females are dangerous to humans.

Description
Female widow spiders are typically dark brown or a shiny black in colour when they are full grown, usually exhibiting a red or orange hourglass on the ventral surface (underside) of the abdomen; some may have a pair of red spots or have no marking at all. The male widow spiders often exhibit various red or red and white markings on the dorsal surface (upper side) of the abdomen, ranging from a single stripe to bars or spots, and juveniles are often similar to the male pattern. Females of a few species are paler brown and some have no bright markings. The bodies of black widow spiders range from 3-10 mm in size; some females can measure 13 mm in their body length (not including legs). Including legs, female adult black widows generally measure 1 - 1.5 in.

Behaviour
The prevalence of sexual cannibalism, a behaviour in which the female eats the male after mating, has inspired the common name "widow spiders". This behaviour may promote the survival odds of the offspring; however, females of some species only rarely show this behaviour, and much of the documented evidence for sexual cannibalism has been observed in laboratory cages where the males could not escape. Male black widow spiders tend to select their mates by determining if the female has eaten already to avoid being eaten themselves. They are able to tell if the female has fed by sensing chemicals in the web. Latrodectus hesperus is referred to as an "opportunistic cannibal" because in dire situations it will resort to cannibalism. In addition to sexual cannibalism, Latrodectus hesperus are also known to engage in sibling cannibalism.

Like other members of the Theridiidae, widow spiders construct a web of irregular, tangled, sticky silken fibres. Black widow spiders prefer to nest near the ground in dark and undisturbed areas, usually in small holes produced by animals, or around construction openings or woodpiles. Indoor nests are in dark, undisturbed places such as under desks or furniture or in a basement. The spider frequently hangs upside down near the centre of its web and waits for insects to blunder in and get stuck. Then, before the insect can extricate itself, the spider rushes over to envenomate and wrap it in silk. To feed, the spider's mouth pulses digestive juices over the prey, which liquifies, which the spider internalizes by capillary action, sucking the slurry into its mouth. Their prey consists of small insects such as flies, mosquitoes, grasshoppers, beetles, and caterpillars. If the spider perceives a threat, it quickly lets itself down to the ground on a safety line of silk.

As with other web-weavers, these spiders have very poor eyesight and depend on vibrations reaching them through their webs to find trapped prey or warn them of larger threats. When a widow spider is trapped, it is unlikely to bite, preferring to play dead or flick silk at the potential threat; bites occur when they cannot escape. Many injuries to humans are due to defensive bites delivered when a spider gets unintentionally squeezed or pinched. The blue mud dauber species, Chalybion californicum, is a wasp that, in western North America, is the primary predator of black widow spiders.

The ultimate tensile strength and other physical properties of Latrodectus hesperus (western black widow) silk are similar to the properties of silk from orb-weaving spiders that had been tested in other studies. The tensile strength for the three kinds of silk measured in the Blackledge study was about 1,000 MPa. The ultimate strength reported in a previous study for Trichonephila edulis was 1,290 ± 160 MPa. The tensile strength of spider silk is comparable to that of steel wire of the same thickness. However, as the density of steel is about six times that of silk, silk is correspondingly stronger than steel wire of the same weight.

Spiders of the genus Steatoda (also of the Theridiidae) are often mistaken for widow spiders, and are known as "false widow spiders"; while their bite can be painful, they are significantly less harmful to humans.

Taxonomy

The genus Latrodectus was erected by Charles Athanase Walckenaer in 1805, for the species Latrodectus tredecimguttatus and Latrodectus mactans. Arachnologist Herbert Walter Levi revised the genus in 1959, studying the female sexual organs and noting their similarity across described species. He concluded the colour variations were variable across the world and were not sufficient to warrant species status, and reclassified the redback and several other species as subspecies of the black widow spider.

Levi also noted that study of the genus had been contentious; in 1902, both F. O. Pickard-Cambridge and Friedrich Dahl had revised the genus, with each criticising the other. Cambridge questioned Dahl's separating species on what he considered minor anatomical details, and the latter dismissed the former as an "ignoramus".

Species
the World Spider Catalog accepted the following species:
 * Latrodectus antheratus (Badcock, 1932) – Paraguay, Argentina
 * Latrodectus apicalis Butler, 1877 – Galapagos Islands
 * Latrodectus bishopi Kaston, 1938 – USA
 * Latrodectus cinctus Blackwall, 1865 – Cape Verde Is., Africa, Kuwait, Iran
 * Latrodectus corallinus Abalos, 1980 – Argentina
 * Latrodectus curacaviensis (Müller, 1776) – Lesser Antilles, South America
 * Latrodectus dahli Levi, 1959 – North Africa, Cyprus, Turkey, Azerbaijan, Kazakhstan, Middle East, Iran, Central Asia
 * Latrodectus diaguita Carcavallo, 1960 – Argentina
 * Latrodectus elegans Thorell, 1898 – India, Myanmar, Thailand, China, Japan
 * Latrodectus erythromelas Schmidt & Klaas, 1991 – India, Sri Lanka
 * Latrodectus garbae Rueda & Realpe, 2021 – Colombia
 * Latrodectus geometricus C. L. Koch, 1841 – Africa. Introduced to both Americas, Poland, Middle East, Pakistan, India, Thailand, Japan, China, Papua New Guinea, Australia, Hawaii
 * Latrodectus hasselti Thorell, 1870 – Southeast Asia to Australia. Introduced to Iran, Pakistan, India, Japan, New Zealand
 * Latrodectus hesperus Chamberlin & Ivie, 1935 – Canada, USA, Mexico. Introduced to Israel, Korea
 * Latrodectus hurtadoi Rueda & Realpe, 2021 – Colombia
 * Latrodectus hystrix Simon, 1890 – Yemen (mainland, Socotra)
 * Latrodectus indistinctus O. Pickard-Cambridge, 1904 – Namibia, South Africa
 * Latrodectus karrooensis Smithers, 1944 – South Africa
 * Latrodectus katipo Powell, 1871 – New Zealand
 * Latrodectus lilianae Melic, 2000 – Spain, Algeria?
 * Latrodectus mactans (Fabricius, 1775) – Probably native to North America only. Introduced to South America, Asia
 * Latrodectus menavodi Vinson, 1863 – Madagascar, Comoros, Seychelles (Aldabra)
 * Latrodectus mirabilis (Holmberg, 1876) – Argentina
 * Latrodectus obscurior Dahl, 1902 – Cape Verde Is., Madagascar
 * Latrodectus occidentalis Valdez-Mondragón, 2023 – Mexico
 * Latrodectus pallidus O. Pickard-Cambridge, 1872 – Cape Verde Is. to Libya, Turkey, Kazakhstan, Iran, Central Asia
 * Latrodectus quartus Abalos, 1980 – Argentina
 * Latrodectus renivulvatus Dahl, 1902 – Africa, Yemen, Saudi Arabia, Iraq
 * Latrodectus revivensis Shulov, 1948 – Israel, Iran, possibly the Canary Islands
 * Latrodectus rhodesiensis Mackay, 1972 – Southern Africa
 * Latrodectus thoracicus Nicolet, 1849 – Chile
 * Latrodectus tredecimguttatus (Rossi, 1790) (type) – Mediterranean, Ukraine, Caucasus, Russia (Europe to South Siberia), Kazakhstan, Iran, Central Asia, China
 * Latrodectus umbukwane B. M. O. G. Wright, C. D. Wright, Lyle & Engelbrecht, 2019 – South Africa
 * Latrodectus variegatus Nicolet, 1849 – Chile, Argentina
 * Latrodectus variolus Walckenaer, 1837 – USA, Canada

Nomina dubia
 * L. dotatus C. L. Koch, 1841
 * L. limacidus Cantor, 1842
 * L. pallidus Caporiacco, 1933

Distribution
Widow spiders are found on every continent of the world except Antarctica. In North America, the black widows commonly known as southern (Latrodectus mactans), western (Latrodectus hesperus), and northern (Latrodectus variolus) are found in the United States, equally in western México (Latrodectus occidentalis), as well as parts of southern Canada – particularly in the Okanagan Valley of British Columbia, as are the "grey" or "brown widow spiders" (Latrodectus geometricus) and the "red widow spiders" (Latrodectus bishopi).

The most prevalent species occurring in eastern Asia and Australia is commonly called the redback (Latrodectus hasselti).

They are often confused with spiders in the genus Steatoda, known as false widow spiders, due to their similar appearance.

Venom
Due to the presence of latrotoxin in their venom, black widow bites are potentially dangerous and may result in systemic effects (latrodectism) including severe muscle pain, abdominal cramps, diaphoresis, tachycardia, and muscle spasms. Symptoms usually last for 3–7 days, but may persist for several weeks. In 1933, a University of Alabama medical faculty, Allan Blair conducted an experiment on himself to document the symptoms of a black widow bite, and to test whether someone can build immunity after being bitten. The effects of the bite were so painful and harsh that Blair failed to complete the experiment and did not follow through with being bitten a second time.

In the United States each year, about 2,500 people report being bitten by a black widow, but most do not need medical treatment. Some bites have no venom injected—a "dry" bite. In the United States, no deaths due to black widows have been reported to the American Association of Poison Control Centers since 1983. Black widows are not especially aggressive spiders, and they rarely bite humans unless startled or otherwise threatened.

Contrary to popular belief, most people who are bitten suffer no serious damage, let alone death. Fatal bites were reported in the early 20th century mostly with Latrodectus tredecimguttatus, the Mediterranean black widow.

Since the venom is not usually life-threatening, antivenom has been used as pain relief and not to save lives. However, a study demonstrated that standardized pain medication, when combined with either antivenom or a placebo, had similar improvements in pain and resolution of symptoms.

title: Latrodectus


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Anthracene

Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula C14H10, consisting of three fused benzene rings. It is a component of coal tar. Anthracene is used in the production of the red dye alizarin and other dyes. Anthracene is colorless but exhibits a blue (400–500 nm peak) fluorescence under ultraviolet radiation.

Occurrence and production
Coal tar, which contains around 1.5% anthracene, remains a major source of this material. Common impurities are phenanthrene and carbazole. The mineral form of anthracene is called freitalite and is related to a coal deposit. A classic laboratory method for the preparation of anthracene is by cyclodehydration of o-methyl- or o-methylene-substituted diarylketones in the so-called Elbs reaction, for example from o-tolyl phenyl ketone.

Reduction
Reduction of anthracene with alkali metals yields the deeply colored radical anion salts M+[anthracene]− (M = Li, Na, K). Hydrogenation gives 9,10-dihydroanthracene, preserving the aromaticity of the two flanking rings.

Cycloadditions
In any solvent except water, anthracene photodimerizes by the action of UV light:
 * [[Image:Anthracene Photodimerisation.svg|360px|Anthracene dimer]]

The dimer, called dianthracene (or sometimes paranthracene), is connected by a pair of new carbon-carbon bonds, the result of the [4+4] cycloaddition. It reverts to anthracene thermally or with UV irradiation below 300 nm. Substituted anthracene derivatives behave similarly. The reaction is affected by the presence of oxygen.

Anthracene also reacts with dienophile singlet oxygen in a [4+2]-cycloaddition (Diels–Alder reaction):
 * [[Image:Anthracene singlet oxygen Diels-Alder reaction.svg|360px|none|Diels alder reaction of anthracene with singlet oxygen]]

With electrophiles
Chemical oxidation occurs readily, giving anthraquinone, C14H8O2 (below), for example using hydrogen peroxide and vanadyl acetylacetonate.
 * [[Image:Anthraquinone acsv.svg|120px|none|Anthraquione]]

Electrophilic substitution of anthracene occurs at the 9 position. For example, formylation affords 9-anthracenecarboxaldehyde. Substitution at other positions is effected indirectly, for example starting with anthroquinone. Bromination of anthracene gives 9,10-dibromoanthracene.

Uses
Anthracene is converted mainly to anthraquinone, a precursor to dyes.

Niche
Anthracene, a wide band-gap organic semiconductor is used as a scintillator for detectors of high-energy photons, electrons and alpha particles. Plastics, such as polyvinyltoluene, can be doped with anthracene to produce a plastic scintillator that is approximately water-equivalent for use in radiation therapy dosimetry. Anthracene's emission spectrum peaks at between 400 nm and 440 nm.

It is also used in wood preservatives, insecticides, and coating materials.

Anthracene is commonly used as a UV tracer in conformal coatings applied to printed wiring boards. The anthracene tracer allows the conformal coating to be inspected under UV light.

 * Fluorescence of Anthracene under UV light.jpg

Derivatives
A variety of anthracene derivatives find specialized uses. Derivatives having a hydroxyl group are 1-hydroxyanthracene and 2-hydroxyanthracene, homologous to phenol and naphthols, and hydroxyanthracene (also called anthrol, and anthracenol) are pharmacologically active. Anthracene may also be found with multiple hydroxyl groups, as in 9,10-dihydroxyanthracene.

Some anthracene derivatives are used as pharmaceutical drugs, including bisantrene, trazitiline, and benzoctamine.

Occurrence
Anthracene, as many other polycyclic aromatic hydrocarbons, is generated during combustion processes. Exposure to humans happens mainly through tobacco smoke and ingestion of food contaminated with combustion products.

Toxicology
Many investigations indicate that anthracene is noncarcinogenic: "consistently negative findings in numerous in vitro and in vivo genotoxicity tests". Early experiments suggested otherwise because crude samples were contaminated with other polycyclic aromatic hydrocarbons. Furthermore, it is readily biodegraded in soil. It is especially susceptible to degradation in the presence of light.

title: Anthracene