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Zirconium is a chemical element with the symbol Zr and atomic number 40. The name zirconium is taken from the name of the mineral zircon, the most important source of zirconium, it is a lustrous, grey-white, strong transition metal that resembles hafnium and, to a lesser extent, titanium. Zirconium is used as a refractory and opacifier, although small amounts are used as an alloying agent for its strong resistance to corrosion. Zirconium forms a variety of inorganic and organometallic compounds such as zirconium dioxide and zirconocene dichloride, respectively. Five isotopes occur three of which are stable. Zirconium compounds have no known biological role. Zirconium is a lustrous, greyish-white, ductile, malleable metal, solid at room temperature, though it is hard and brittle at lesser purities. In powder form, zirconium is flammable, but the solid form is much less prone to ignition. Zirconium is resistant to corrosion by alkalis, salt water and other agents. However, it will dissolve in hydrochloric and sulfuric acid when fluorine is present.

Alloys with zinc are magnetic at less than 35 K. The melting point of zirconium is 1855 °C, the boiling point is 4371 °C. Zirconium has an electronegativity of 1.33 on the Pauling scale. Of the elements within the d-block with known electronegativities, zirconium has the fifth lowest electronegativity after hafnium, yttrium and actinium. At room temperature zirconium exhibits a hexagonally close-packed crystal structure, α-Zr, which changes to β-Zr, a body-centered cubic crystal structure, at 863 °C. Zirconium exists in the β-phase until the melting point. Occurring zirconium is composed of five isotopes. 90Zr, 91Zr, 92Zr and 94Zr are stable, although 94Zr is predicted to undergo double beta decay with a half-life of more than 1.10×1017 years. 96Zr has a half-life of 2.4×1019 years, is the longest-lived radioisotope of zirconium. Of these natural isotopes, 90Zr is the most common. 96Zr is the least common, comprising only 2.80% of zirconium. Twenty-eight artificial isotopes of zirconium have been synthesized, ranging in atomic mass from 78 to 110.

93Zr is the longest-lived artificial isotope, with a half-life of 1.53×106 years. 110Zr, the heaviest isotope of zirconium, is the most radioactive, with an estimated half-life of 30 milliseconds. Radioactive isotopes at or above mass number 93 decay by electron emission, whereas those at or below 89 decay by positron emission; the only exception is 88Zr. Five isotopes of zirconium exist as metastable isomers: 83mZr, 85mZr, 89mZr, 90m1Zr, 90m2Zr and 91mZr. Of these, 90m2Zr has the shortest half-life at 131 nanoseconds. 89mZr is the longest lived with a half-life of 4.161 minutes. Zirconium has a concentration of about 130 mg/kg within the Earth's crust and about 0.026 μg/L in sea water. It is not found in nature as a native metal, reflecting its intrinsic instability with respect to water; the principal commercial source of zirconium is zircon, a silicate mineral, found in Australia, India, South Africa and the United States, as well as in smaller deposits around the world. As of 2013, two-thirds of zircon mining occurs in South Africa.

Zircon resources exceed 60 million tonnes worldwide and annual worldwide zirconium production is 900,000 tonnes. Zirconium occurs in more than 140 other minerals, including the commercially useful ores baddeleyite and kosnarite. Zirconium is abundant in S-type stars, it has been detected in the sun and in meteorites. Lunar rock samples brought back from several Apollo missions to the moon have a high zirconium oxide content relative to terrestrial rocks. Zirconium is a by-product of the mining and processing of the titanium minerals ilmenite and rutile, as well as tin mining. From 2003 to 2007, while prices for the mineral zircon increased from $360 to $840 per tonne, the price for unwrought zirconium metal decreased from $39,900 to $22,700 per ton. Zirconium metal is much more expensive than zircon because the reduction processes are costlyCollected from coastal waters, zircon-bearing sand is purified by spiral concentrators to remove lighter materials, which are returned to the water because they are natural components of beach sand.

Using magnetic separation, the titanium ores ilmenite and rutile are removed. Most zircon is used directly in commercial applications, but a small percentage is converted to the metal. Most Zr metal is produced by the reduction of the zirconium chloride with magnesium metal in the Kroll process; the resulting metal is sintered until sufficiently ductile for metalworking. Commercial zirconium metal contains 1–3% of hafnium, not problematic because the chemical properties of hafnium and zirconium are similar, their neutron-absorbing properties differ however, necessitating the separation of hafnium from zirconium for nuclear reactors. Several separation schemes are in use; the liquid-liquid extraction of the thiocyanate-oxide derivatives exploits the fact that the hafnium derivative is more soluble in methyl isobutyl ketone than in water. This method is used in United States. Zr and Hf can be separated by fractional crystallization of potassium hexafluorozirconate, less soluble in water than the analogous hafnium derivative.

Fractional distillation of the tetrachlorides called extractive distillation, is used in Europe. The product of a quadruple VAM process, combined with hot extruding and different rolling applicatio


Poomalai is 1965 Indian Tamil-language woman's film, directed by P. Neelakantan and written by M. Karunanidhi; the film was produced by Murasoli Maran under Karunanidhi's production company Meghala Pictures, which distributed the film. It stars S. S. Rajendran, C. R. Vijayakumari and Anjali Devi, with S. A. Ashokan and Manorama in supporting roles; the film focuses on the title character, a happy-go-lucky girl whose life changes for the worse when she is raped. It was released on 23 October 1965. Poomalai is a happy-go-lucky girl living with elder brother, her life changes for the worse. S. S. Rajendran as Sundaram C. R. Vijayakumari as Poomalai Anjali Devi as Maragatham Nagesh as Chittu Manorama as Myna S. A. Ashokan as Anand Rajasree as Nalina T. S. Muthaiah as Poomalai and Anand's father V. R. Thilakam as Leela M. S. Bhakkyam as Subbhamma Poomalai was directed by P. Neelakantan, written by M. Karunanidhi and produced by Murasoli Maran under Meghala Pictures. Art direction was handled by B. Nagarajan, cinematography by editing by R. Devarajan.

Karunanidhi appeared as himself onscreen. Although Karunanidhi was the owner of Meghala Pictures, he was not credited as the film's producer. Historian R. Kannan said that Karunanidhi used to ingeniously weave contemporary politics into the dialogues he wrote for films, named a dialogue in Poomalai where the sister speaks of her brother and threatens to shoot anyone speaking ill of him as an example; the soundtrack was composed by R. Sudharsanam; the lyrics were written by Mayavanathan, Kavi Rajagopal, Kumaradevan and M. Karunanidhi. Poomalai was released on 23 October 1965, during that year's Diwali day. Meghala Pictures distributed the film themselves in Madras, while other distributors did so in other districts of Tamil Nadu; the Indian Express wrote on 30 October, "An otherwise loose screenplay is propped up by the beautiful dialogues by M. Karunanidhi and fine portrayals by Rajendran, R. Vijayakumari, veteran Anjali Devi and comedian Nagesh. Neelakantan's direction is nothing to write home about, but with the material at his disposal, he has made it into a good tear-jerker, appealing to family audiences women."

Writing in Sport and Pastime, T. M. Ramachandran lauded the performances of Rajendran and appreciated the performances of Nagesh, Anjali Devi, Ravi, Asokan and Rajsri, he added that Karunanidhi's screenplay and dialogues were the film's "saving graces", but criticised Neelakantan's direction for succumbing to "trivialities and box-office considerations". According to historian Vamanan, the film landed Karunanidhi in deep debt. Poomalai on IMDb Poomalai at Complete Index to World Film

Devil Dog Dawson

Devil Dog Dawson is a 1921 American silent western film directed by Karl R. Coolidge and starring Jack Hoxie, Helene Rosson and Evelyn Selbie, it was released on the states-rights market by Arrow Film Corp.. The film was considered lost; the only surviving footage from this film—38 seconds' worth—was found in a mislabeled tin by a collector in Ohio. The title marked on the tin was Dangerous Hour – Eddie Polo; the canister and its contents were the subject of an investigation in a 2006 episode of the PBS series History Detectives. The film segment was restored by the Library of Congress. Another copy has been since located in Bois d'Arcy Archive. Many remaining scenes from this film were thought to have been cut at the time because they depicted alcohol consumption, illegal at the time. A group of three settlers in Oregon have their horses stolen by outlaws, their horses are returned by three cowboys. The cowboys save the settlers again when they are threatened by farmworkers. Jack Hoxie Helene Rosson Evelyn Selbie Wilbur McGaugh Arthur Mackley "Silent Film Reel" at History Detectives website Devil Dog Dawson on IMDb

The Two Doctors

The Two Doctors is the fourth serial of the 22nd season of the British science fiction television series Doctor Who, first broadcast in three weekly parts on BBC1 from 16 February to 2 March 1985. The serial is set in and around Seville. In the serial, the alien time traveller the Sixth Doctor, his former travelling companion Jamie McCrimmon and his current companion Peri Brown work to save the younger Second Doctor from the biogeneticist Dastari, who intends to steal the knowledge of how to travel in time from the Second Doctor's genetic make-up; the Second Doctor and Jamie McCrimmon land the TARDIS on board Space Station Camera in the Third Zone on a mission for the Time Lords, who have installed a teleport control on the TARDIS. The Doctor explains that the station is a research facility and that they have to talk to Dastari, the Head of Projects; the Androgum cook Shockeye drugs the meals of the station's scientists. The Doctor tells Dastari that the Time Lords want the time experiments of Reimer stopped.

The Doctor warns that the distortions from the Kartz-Reimer experiments are on the verge of threatening the fabric of time, but Dastari refuses to order them to cease, accusing the Time Lords of not wanting another race to discover the secrets of time travel. Dastari and the others collapse from the drugged meals. Chessene, an Androgum technologically augmented to mega-genius levels, lowers the station's defences to allow the Sontarans to attack. Jamie sees. Inside the TARDIS, the Sixth Doctor has a vision of his second incarnation being put to death. Since he is still alive, he is concerned that he may have died in the past and only exists now as a temporal anomaly, he decides to consult his old friend Dastari to see. The Doctor and Peri find no signs of life; the station computer demands that the Doctor leave and, when he refuses, tries to kill him and Peri by depressurising the passageway. The Doctor drags his unconscious companion through to another section; the Doctor discovers Dastari's day journal and the Time Lords' objections to the Kartz-Reimer experiments.

In Spain, Shockeye and a Sontaran, Major Varl, take possession of a hacienda by killing its owner, Doña Arana. Dastari and the Sontaran Group Marshal Stike carry an unconscious Second Doctor towards the hacienda. Peri is attacked by a humanoid in rags; the Sixth Doctor and Peri find that Peri's attacker was Jamie, hiding all the while. Under hypnosis, Jamie tells the Sixth Doctor; the Sixth Doctor explains to Jamie and Peri that what Jamie saw was an illusion designed to make people believe the Doctor was dead and not investigate further. He theorises that the Sontarans kidnapped Dastari as he is the only biogeneticist in the galaxy who could isolate the symbiotic nuclei that gives Time Lords the molecular stability to travel through time; the Sixth Doctor puts himself into a telepathic trance to determine where his past incarnation is being held. He narrows it down to the Seville area. Dastari reveals his plan to dissect the Second Doctor's cell structure to isolate his symbiotic nuclei and give them to Chessene.

The Second Doctor protests that her barbaric Androgum nature, coupled with the ability to time travel, will mean that there will be no limit to her evil. Finding the hacienda, Peri interrupts the operation. Sneaking into the cellar, the Sixth Doctor examines the Kartz-Reimer module, a prototype time machine modelled on Time Lord technology, explaining to Jamie how it works; the Sontarans overhear him. Outside, Shockeye brings her to the hacienda kitchen. Stike threatens to kill Jamie unless the Sixth Doctor gets into the module and primes it with his symbiotic print, the Doctor does so; the Sixth Doctor primes the module, he and Jamie escape the Sontarans. Chessene has a contingency plan after discovering the involvement of two Time Lords, she asks Dastari to implant the Second Doctor with some of Shockeye's genetic material, turning the Doctor into an Androgum. They intend to eliminate the Sontarans. Chessene interrupts Shockeye when he attempts to cook an unconscious Peri, stuns him so that Dastari can remove his genetic material.

The Sixth Doctor revives Peri, tells Jamie and her that what he revealed to the Sontarans was not true — he had lied because he had heard Stike approaching. The machine worked for the Doctor, but will not for them because the Doctor has taken the briode nebuliser. Before they can release the Second Doctor and escape the hacienda, Shockeye shows up with Peri. Dastari has implanted the Second Doctor with a 50 percent Androgum inheritance, when Shockeye wakes in a rage, he finds a kindred spirit in the transformed Doctor, they decide to go into the town to sample the local cuisine. Dastari lures the Sontarans into the cellar. Varl is killed, he tries to use the module, but without the nebuliser, it burns him. Stike staggers towards his battlecraft, forgetting about the self-destruct Varl had set; the ship explodes. The Sixth Doctor and Jamie follow the Second Doctor into Seville, hoping to cure him before the change becomes complete. Dastari and Chessene are looking for them, knowing that unless the Second Doctor undergoes a stabilising operation, he will reject the Androgum transfusion.

The Second Doctor and Shockeye go to Las Cadenas restaurant ordering gargantuan amounts of food. When the restaurant's owner Oscar demands that they pay, Shockeye fatally stabs Oscar, just as the Sixth Doctor

Battle of Venta del Pozo

The Battle of Venta del Pozo known as the Battle of Villodrigo by the French and Spanish, was a rear-guard action fought as part of the Peninsular War on 23 October 1812 between an Anglo-German force led by Major-General Stapleton Cotton against French cavalry under Major-Generals Jean-Baptiste Curto and Pierre François Xavier Boyer. The result was a French tactical victory; the Duke of Wellington's Anglo and Portuguese army gave up its unsuccessful Siege of Burgos on 21 October 1812 and withdrew southwest toward Torquemada. Wellington's 35,000-man army was pursued by Maj-Gen Joseph Souham's reinforced Army of Portugal of 53,000 soldiers. Major-General Stapleton Cotton's rearguard included Colonel Colin Halkett's King's German Legion brigade, Major-General George Anson's light cavalry brigade, Major-General Eberhardt von Bock's heavy cavalry brigade, Norman Ramsay's RHA troop of six cannons; the total strength was 2,800 men. Curto's light cavalry brigade was made up of the 3rd Hussars and the remnants of the 13th, 14th, 22nd, 26th, 28th Chasseurs.

Boyer's dragoon brigade included the 6th, 11th, 15th, 25th Dragoons. Colonel Faverot, in charge of the 15th Chasseurs and Duchy of Berg Light Horse Lancers, Colonel Béteille, head of the élite Gendarmes rode with the advanced guard; the French force numbered 3,200 men. On 23 October, Cotton drew up his cavalry in front of a stone bridge where the main highway crossed a deep, dry streambed, he planned to ambush the French advanced guard. As the French approached, Anson's cavalry would file across the bridge and the French would follow. After the French had crossed, Ramsay's guns would open fire on them and Bock's dragoons would charge them. Meanwhile, on the British left flank, Curto's hussars had crossed the dry stream bed further upstream and attacked mounted Spaniards under the command of Marquinez posted on the hills overlooking the battlefield; as the Spaniards came pouring down the hills pursued by the French hussars, the whole mass fell upon the 16th Light Dragoon, charged by French dragoons that had crossed the bridge.

The 16th Light Dragoon fell back in complete confusion and turned the wrong way, blocking both Ramsay's guns and Bock's intended charge zone. The Lancers of Berg, 15th Chasseurs, Gendarmes arrived in line towards the stream bed, which they found impassable, they turned right, trotted over the bridge, turned left, formed a line in front of Bock's heavy cavalry brigade. The Berg lancer squadron posted itself closest to the bridge, followed by the five squadrons of the 15th Hussars, the four Gendarme squadrons. At 17:00, before the last two Gendarme squadrons had finished positioning themselves, Bock's Dragoons attacked in two lines; the first line of three squadrons was reeling back. Just before this charge, the last two Gendarme squadrons had managed to place themselves in such a way as to attack both Dragoon lines on their right flank. Eight to ten minutes of bitter fighting ensued, overlooked by both armies on the surrounding heights. Bock's men retreated followed by Anson's brigade, they soon became outflanked on both sides as more French dragoons came racing down upon them, causing the British cavalry to break in complete confusion.

They rallied behind Halkett's two KGL infantry battalions as the Gendarmes, 15th Chasseurs, Berg Lancers halted to rally themselves. Boyer's Dragoons broke Bock's dragoons a second time. Wellington, arriving on the field directed Halkett's squares to fire at the French Dragoons, which unsuccessfully charged the squares three times before pulling away; the arrival of French infantry forced the Anglo-German force to retreat, but in good order. Cotton distinguished himself by his "coolness and gallantry."The Allies lost 165 killed and wounded and 65 captured. The French lost between 300 casualties. Other sources state 250 killed and wounded for the Allies and 85 prisoners, five of which were officers, while the French had 7 killed and 134 wounded. One of them was Colonel Jean-Alexis Béteille, left for dead on the field after receiving twelve sword wounds. French surgeons managed to save him. Several months he was made brigadier general and officer of the Légion d'honneur by Napoleon himself; the German 1st and 2nd KGL Light battalions wore the "Venta del Pozo" battle honour until 1918 in their subsequent service with the Hanoverian and Prussian armies.

Chapell, Mike. The King's German Legion 1812–1816. Osprey. ISBN 1-85532-997-2. Gates, David; the Spanish Ulcer: A History of the Peninsular War. Da Capo Press. ISBN 0-306-81083-2. Glover, Michael; the Peninsular War 1807–1814. London: Penguin. ISBN 0-14-139041-7. Smith, Digby; the Napoleonic Wars Data Book. London: Greenhill. ISBN 1-85367-276-9. Tranié, J.. B.. Napoleon – La Campagne d'Espagne. Copernic. Beamish, N. Ludlow. History of the King's German Legion Vol. 2. Naval and Military Press. ISBN 0-9522011-0-0. Martin, E.. La Gendarmerie Française en Espagne et en Portugal. Terana. ISBN 2-904221-24-7. Napier, W.. History of the Peninsular War, Vol.3. Carey and Hart


Cherryburn is a cottage in Mickley, England, the birthplace of Thomas Bewick, an English wood engraver and ornithologist. The cottage, its adjacent farmhouse and large grounds, have been managed by the National Trust since 1991 when they took over responsibility for the site from the Bewick Birthplace Trust. Cherryburn is now open to the public 7 days a week between November. Thomas Bewick was born in the cottage in August 1753, he grew up there until the age of 14 when he moved to Newcastle upon Tyne to become a bound apprentice with the Beilby family; the Cottage and the Farmhouse are now a museum to show what life was back when Thomas Bewick was alive. The Cottage has been furnished with items which would have been common at the time and the Farmhouse possesses a large collection of Bewick's publications, original engravings and printing equipment. Cherryburn's entry on the National Trust website