Haarlem is a city and municipality in the Netherlands. It is the capital of the province of North Holland and is situated at the northern edge of the Randstad, one of the most populated metropolitan areas in Europe. Haarlem had a population of 161,265 in 2019. Haarlem was granted city status or stadsrechten in 1245, although the first city walls were not built until 1270; the modern city encompasses the former municipality of Schoten as well as parts that belonged to Bloemendaal and Heemstede. Apart from the city, the municipality of Haarlem includes the western part of the village of Spaarndam. Newer sections of Spaarndam lie within the neighbouring municipality of Haarlemmermeer; the city is located on the river Spaarne, giving it its nickname'Spaarnestad'. It is situated about 20 km west near the coastal dunes. Haarlem has been the historical centre of the tulip bulb-growing district for centuries and bears its other nickname'Bloemenstad' for this reason. Haarlem has a rich history dating back to pre-medieval times, as it lies on a thin strip of land above sea level known as the strandwal, which connects Leiden to Alkmaar.

The people on this narrow strip of land struggled against the waters of the North Sea from the west, the waters of the IJ and the Haarlem Lake from the east. Haarlem became wealthy with toll revenues that it collected from ships and travellers moving on this busy North-South route. However, as shipping became important economically, the city of Amsterdam became the main Dutch city of North Holland during the Dutch Golden Age; the town of Halfweg became a suburb, Haarlem became a quiet bedroom community, for this reason Haarlem still has many of its central medieval buildings intact. Nowadays many of them are on the Dutch Heritage register known as Rijksmonuments; the list of Rijksmonuments in Haarlem gives an overview of these per neighbourhood, with the majority in the old city centre. The oldest mentioning of Haarlem dates from the 10th century; the name comes from "Haarlo-heim". This name is composed of three elements: lo and heim. There is not much dispute about the meaning of heim. Haar, has several meanings, one of them corresponding with the location of Haarlem on a sand dune:'elevated place'.

The name Haarlem or Haarloheim would therefore mean'home on a forested dune'. There was a stream called "De Beek", dug from the peat grounds west of the river Spaarne as a drainage canal. Over the centuries the Beek was turned into an underground canal, as the city grew larger and the space was needed for construction. Over time it began to silt up and in the 19th century it was filled in; the location of the village was a good one: by the river Spaarne, by a major road going south to north. By the 12th century it was a fortified town, Haarlem became the residence of the Counts of Holland. In 1219 the knights of Haarlem were laurelled by Count Willem I, because they had conquered the Egyptian port of Damietta in the fifth crusade. Haarlem received the right to cross in its coat of arms. On 23 November 1245 Count Willem II granted Haarlem city rights; this implied a number of privileges, among which the right for the sheriff and magistrates to administer justice, instead of the Count. This allowed for a quicker and more efficient judiciary system, more suited to the needs of the growing city.

After a siege from the surrounding area of Kennemerland in 1270 a defensive wall was built around the city. Most this was an earthen wall, with wooden gates; the city started out between Spaarne, Ridderstraat and Naussaustraat. In the 14th century the city expanded, the Burgwalbuurt and the area around the Oudegracht became part of the city; the old defenses proved not to be sufficiently strong for the expanded city, at the end of the 14th century a 16½-metre high wall was built, complete with a 15-metre wide canal circling the city. In 1304 the Flemish threatened the city. All the city's buildings were made of wood, fire was a great risk. In 1328 nearly the whole city burnt down; the Sint-Bavokerk was damaged, rebuilding it would take more than 150 years. Again on 12 June 1347 there was a fire in the city. A third large fire, in 1351, destroyed many buildings including the Count's castle and the city hall; the Count did not need a castle in Haarlem because his castle in Den Haag had taken over all functions.

The Count donated the ground to the city and a new city hall was built there. The shape of the old city was square—this was inspired by the shape of ancient Jerusalem. After every fire the city was rebuilt an indication of the wealth of the city in those years; the Black Death came to the city in 1381. According to an estimate by a priest from Leiden the disease killed 5,000 people, about half the population at that time. In the 14th century Haarlem was a major city, it was the second largest city in historical Holland after Dordrecht and before Delft, Amsterdam and Rotterdam. In 1429 the city gained the right to collect tolls, including ships passing the city on the Spaarne river. At the end of the Middle Ages Haarlem was a flourishing city with a large textile industry and beer breweries. Around 1428 the city was put under siege by the army of Countess of Hainaut. Haarlem had taken side with the Cods in the Hook and Cod wars, thus against Jacoba of Bavaria; the entire Haarlemmerho

Isotopes of tungsten

Occurring tungsten consists of five isotopes. Four are considered stable and one is radioactive, 180W, with an long half-life of 1.8 ± 0.2 Ea. On average, two alpha decays of 180W occur per gram of natural tungsten per year, so for most practical purposes, tungsten can be considered stable. Theoretically, all five can decay into isotopes of element 72 by alpha emission, but only 180W has been observed to do so; the other occurring isotopes have not been observed to decay, lower bounds for their half lives have been established: 182W, t1/2 > 7.7×1021 years183W, t1/2 > 4.1×1021 years184W, t1/2 > 8.9×1021 years186W, t1/2 > 8.2×1021 yearsThirty-three artificial radioisotopes of tungsten have been characterized with mass numbers ranging from 157 to 194, the most stable of which are 181W with a half-life of 121.2 days, 185W with a half-life of 75.1 days, 188W with a half-life of 69.4 days and 178W with a half-life of 21.6 days. All of the remaining radioactive isotopes have half-lives of less than 24 hours, most of these have half-lives that are less than 8 minutes.

Tungsten has 11 meta states with mass numbers of 158, 179, with 3, 180, with 2, 183, 185, 186, with 2, 190, the most stable being 179m1W. Isotope masses from: Audi, Georges. P.. "Atomic weights of the elements. Review 2000". Pure and Applied Chemistry. 75: 683–800. Doi:10.1351/pac200375060683. Wieser, Michael E.. "Atomic weights of the elements 2005". Pure and Applied Chemistry. 78: 2051–2066. Doi:10.1351/pac200678112051. Lay summary. Half-life and isomer data selected from the following sources. Audi, Georges. "NuDat 2.x database". Brookhaven National Laboratory. Holden, Norman E.. "11. Table of the Isotopes". In Lide, David R.. CRC Handbook of Chemistry and Physics. Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9

Dunlop Rubber

Dunlop Rubber was a multinational company involved in the manufacture of various rubber goods. Its business was founded in 1889 by Harvey du Cros and he involved John Boyd Dunlop who had invented and developed the first pneumatic tyre, it was one of the first multinationals, under du Cros and, after him, under Eric Geddes, grew to be one of the largest British industrial companies. J B Dunlop had dropped any ties to it; the business and manufactory was founded in Upper Stephens Street in Dublin. A plaque marks the site, now part of the head office of the Irish multinational departments store brand, Dunnes Stores. Dunlop Rubber and lesibana Tevin Ramasobane failed to adapt to evolving market conditions in the 1970s despite having recognised by the mid 1960s the potential drop in demand as the new much more durable tyres swept throughout the market. After taking on excessive debt Dunlop was acquired by the industrial conglomerate BTR in 1985. Since ownership of the Dunlop trade-names has been fragmented.

In 1888, John Boyd Dunlop, a Scottish veterinary surgeon living in Ireland discovered the pneumatic tyre principle. Willie Hume created publicity for J B Dunlop's discovery by winning seven out of eight races with his pneumatic tyres. To own the rights and exploit the discovery, the Pneumatic Tyre and Booth's Cycle Agency Co. Ltd was incorporated in 1889 and floated by Harvey du Cros, who was, amongst other things, president of the Irish Cyclists' Association; the invitation to du Cros to participate was made by a Dublin cycle agent. J B Dunlop who could see no prosperous future in his discovery, had informally made over his rights to Bowden. J B Dunlop held a 20 percent stake in the venture; the company and manufactory was first founded in Stephens Street in Dublin. The late 1880s was a period of great demand for John Kemp Starley's new safety bicycles. Pneumatic Tyre began cycle tyre production in Belfast in late 1890, expanded to fill consumer demand. However, in 1890, J B Dunlop's patent was withdrawn.

It had been discovered that Robert William Thomson had first patented the pneumatic tyre in 1845. J B Dunlop and Harvey du Cros together worked through the ensuing considerable difficulties, they employed inventor Charles Kingston Welch and acquired other rights and patents which allowed them to protect their business's position to some extent. In the early 1890s, Pneumatic Tyre established divisions in Europe and North America, sending there four of du Cros's six sons. Factories were established overseas because foreign patents rights would only be maintained if the company was engaged in active manufacture where its tyres were sold. Pneumatic Tyre partnered with local cycle firms such as Clement Cycles in France and Adler in Germany in order to limit the necessary capital expenditure. An American business was established in the USA in 1893 with a factory in Buffalo, New York after Harvey du Cros junior was old enough to sign the necessary deeds. In 1893 home manufacture was relocated from Belfast and Dublin to Coventry, the centre of the British cycle industry.

The Dublin Corporation had launched a case against Pneumatic Tyre, claiming nuisance from the smell of rubber and naphtha. Pneumatic Tyre soon spread developing interests in Birmingham; the following year a major interest was taken in their component supplier Byrne Bros India Rubber of Lichfield Road, Aston Birmingham. The same year du Cros started Cycle Components Manufacturing in Selly Oak to supply inner tubes. J B Dunlop resigned in 1895, sold most of his interest in Pneumatic Tyre. In 1896 Harvey Du Cros persuaded his board to sell Pneumatic Tyre to financier Ernest Terah Hooley for £3 million. Hooley drummed up support by offering financial journalists cheap shares and appointing aristocrats to the board, sold the business again, this time as the Dunlop Pneumatic Tyre Company, for £5 million, providing a gross profit to Hooley's syndicate including du Cros of £1.7 million. Associate and supplier Byrne Bros India Rubber, at their Manor Rubber Mills, Aston Cross, had moved from making tyre and tube components to complete inner tubes and covers.

In June 1896 du Cros formed Rubber Tyre Manufacturing, to acquire Byrne Bros.. E J Byrne was contracted to be managing director for five years. From the late 1890s, Dunlop Pneumatic Tyre began to acquire its own rubber mills, began to process rubber, whereas it had assembled tyres using components from other manufacturers. In 1901 Dunlop Pneumatic Tyre used its majority holding to rename Rubber Tyre Manufacturing to Dunlop Rubber. Arthur Du Cros replaced E J Byrne. From 1900, Dunlop began to diversify from cycle tyres; the company manufactured its first motor car tyre in 1900. In 1906, a car wheel manufacturing plant was built. In 1910 Dunlop developed its first aeroplane golf ball. Between 1904 and 1909, the French Dunlop subsidiary lost a total of £200,000, as European rivals such as Michelin of France and Continental of Germany overtook it in the motor tyre market. In 1909, Dunlop of France, in 1910, Dunlop of Germany were wholly acquired by the British parent in order to enforce stronger quality control.

In August 1912 Dunlop Pneumatic Tyre went out of business though retaining certain financial commitments. It passed its activities to Dunlop Rubber in exchange for shares, it changed its name to The Parent Tyre Company Limited. Dunlop Rubber purchased certain of its assets including goodwill and trading rights, in exchange the tyre company shareholders now owned three-quarters of Dunlop Rubber; the amalgamation was intended to bring about a substantial reduction in overhead and clarify what had been seen as a confusing relationship between the two enterprises when they shared most shareho