Oxalate is the dianion with the formula C2O2−4 written 2−2. Either name is used for derivatives, such as salts of oxalic acid, for example sodium oxalate Na2C2O4, or dimethyl oxalate. Oxalate forms coordination compounds where it is sometimes abbreviated as ox. Many metal ions form insoluble precipitates with oxalate, a prominent example being calcium oxalate, the primary constituent of the most common kind of kidney stones; the dissociation of protons from oxalic acid proceeds in a stepwise manner as for other polyprotic acids. Loss of a single proton results in the monovalent hydrogenoxalate anion HC2O−4. A salt with this anion is sometimes called monobasic oxalate, or hydrogen oxalate; the equilibrium constant for loss of the first proton is 5.37×10−2. The loss of the second proton, which yields the oxalate ion, has an equilibrium constant of 5.25×10−5. These values imply, in solutions with neutral pH, no oxalic acid and only trace amounts of hydrogen oxalate exist; the literature is unclear on the distinction between H2C2O4, HC2O−4, C2O2−4, the collection of species is referred to as oxalic acid.
X-ray crystallography of simple oxalate salts show that the oxalate anion may adopt either a planar conformation with D2h molecular symmetry, or a conformation where the O–C–C–O dihedrals approach 90° with approximate D2d symmetry. The oxalate moiety adopts the planar, D2h conformation in the solid-state structures of M2C2O4. However, in structure of Cs2C2O4 the O–C–C–O dihedral angle is 81°. Therefore, Cs2C2O4 is more approximated by a D2d symmetry structure because the two CO2 planes are staggered. Two forms of Rb2C2O4 have been structurally characterized by single-crystal X-ray diffraction; as the preceding examples indicate that the conformation adopted by the oxalate dianion is dependent upon the size of the alkali metal to which it is bound, some have explored the barrier to rotation about the central C−C bond. The barrier to rotation about this bond was determined computationally to be 2–6 kcal/mol for the free dianion, C2O2−4; such results are consistent with the interpretation that the central carbon–carbon bond is best regarded as a single bond with only minimal pi interactions between the two CO−2 units.
This barrier to rotation about the C−C bond may be attributed to electrostatic interactions as unfavorable O−O repulsion is maximized in the planar form. Oxalate is encountered as a bidentate, chelating ligand, such as in potassium ferrioxalate; when the oxalate chelates to a single metal center, it always adopts the planar conformation. Oxalate occurs in many plants. Oxalate-rich plants include fat hen and several Oxalis species; the root and/or leaves of buckwheat are high in oxalic acid. Other edible plants that contain significant concentrations of oxalate include, in decreasing order, star fruit, black pepper, poppy seed, spinach, beets, chocolate, most nuts, most berries, fishtail palms, New Zealand spinach, beans. Leaves of the tea plant contain among the greatest measured concentrations of oxalic acid relative to other plants. However, the beverage derived by infusion in hot water contains only low to moderate amounts of oxalic acid due to the small mass of leaves used for brewing. In the body, oxalic acid combines with divalent metallic cations such as calcium and iron to form crystals of the corresponding oxalates which are excreted in urine as minute crystals.
These oxalates can form larger kidney stones. An estimated 80% of kidney stones are formed from calcium oxalate; those with kidney disorders, rheumatoid arthritis, or certain forms of chronic vulvar pain are advised to avoid foods high in oxalic acid. Methods to reduce the oxalate content in food are of current interest. Magnesium oxalate is 567 times more soluble than calcium oxalate, so the latter is more to precipitate out when magnesium levels are low and calcium and oxalate levels are high. Magnesium oxalate is a million times more soluble than mercury oxalate. Oxalate solubility for metals decreases in the order; the insoluble iron oxalate appears to play a major role in gout, in the nucleation and growth of the otherwise soluble sodium urate. This explains why gout appears after age 40, when ferritin levels in blood exceed 1 μg/L. Foods high in oxalate should be avoided by people suffering at risk of gout. Cadmium catalyzes the transformation of vitamin C into oxalic acid; this can be a problem for people exposed to high levels of cadmium in their diets, in the workplace, or through smoking.
In studies with rats, calcium supplements given along with foods high in oxalic acid can cause calcium oxalate to precipitate in the gut and reduce the levels of oxalate absorbed by the body. Oxalic acid can be produced by the metabolism of ethylene glycol, glyoxylic acid, or ascorbic acid. Powdered oxalate is used as a pesticide in beekeeping to combat the bee mite; some fungi of the genus Aspergillus produce oxalic acid. Some preliminary evidence indicates the administration of probiotics can affect oxalic acid excretion rates in a positive manner. Oxalate, the conjugate base of oxalic acid, is an excellent ligand for metal ions
The Heavy Tank T29 and Heavy Tank T34 were American heavy tanks projects started in March 1944 to counter the appearance of the German Tiger II heavy tank. The T26E3 medium tank, weighed around 45 short tons, but was not considered enough armed or armored to counter the Tiger II, which weighed closer to 69 t; the T29 was not ready in time for the war in Europe, but it did provide post-war engineers with opportunities for applying engineering concepts to artillery and automotive components. The T29 was based upon a lengthened version of the T26E3 chassis and featured heavier armor, an upgraded Ford GAC engine producing about 770 bhp gross, 650 bhp net, more comfortable controls for the driver, a massive new turret incorporating the high-velocity 105 mm gun T5, it weighed 132,000 lb unstowed and 141,000 lb combat loaded. Its maximum armor thickness was 279 mm compared to 180 mm on the German Tiger II while its 105 mm gun was 7.06 m long compared to the 6.29 m of the Tiger II's 88 mm. Other trial models had Allison V1710 V12 engines.
The T29 featured a coincidence rangefinder projecting from both sides of the turret, distinctively resembling "ears". The procurement of 1,200 T29s was proposed on 1 March 1945, revised to 1,152 on 12 April 1945, but by shortly after the end of World War II, only one T29 had been produced, with a second completed. In August 1945, the order was cancelled and it was intended to procure ten T29s for postwar testing; this number was reduced to eight in July 1947. Developed at the same time and related to the T29, the T30 Heavy Tank was identical, but was mounted with the 155 mm gun T7, featured a more powerful engine, an had an additional crew member to help load the heavy ammunition for the gun. Two vehicles were produced; the final variation of the T29 concept, the heavy tank T34, mounted a 120 mm gun based upon the then-current 120mm M1 anti-aircraft gun to further increase the armor penetration capability of the T29. This gun was designated as the 120 mm T53, which could achieve a maximum rate of fire of 5 rounds per minute with two loaders.
With solid shot weighing 50 lb, it had a muzzle velocity of 3,150 ft/s. A lightweight HVAP round with a muzzle velocity of 4,100 ft/s was in development. In order to balance out the weight of the longer and heavier cannon, an additional 101 mm of armour was welded on the rear of the turret bustle; the end of the war curtailed further development, only two prototypes were built. The experience gained. There are several surviving T29s at Georgia, they are being stored in preparation for an Armor exhibit. One has the distinctive rangefinder. Both can be seen as well as many other vehicles in a fenced enclosure on 25 Infantry Regiment Road. One is located in front of the National Cavalry Museum. There is a surviving T29 without the rangefinder at the Detroit Arsenal in Warren, Michigan. List of U. S. military vehicles by model number Military technology and equipment T32 heavy tank - prototype with a similar design.
Justin Francis is an English activist and social entrepreneur. He is the co-founder and CEO of responsibletravel.com, an activist travel company, selling holidays from around the world and publishing online travel guides and responsible tourism related content. Justin Francis was born in 1965 in Wimbledon and grew up in Bathford, Somerset, he studied Geophysics at The University of Exeter after which he worked at advertising agency J. Walter Thompson for eight years, he joined The Body Shop as Social and Environmental Agenda Marketing Manager in 1997 and went on to head up Worldwide Marketing Communications, working with Dame Anita Roddick. Inspired by a nine month stint camping and travelling around Africa, Francis went back to university in 1999 to study for a Masters in Tourism and Sustainable Development at The University of Greenwich, he set up responsibletravel.com in April 2001 with Dr. Harold Goodwin. Dame Anita Roddick was a seed investor offering funds as well as advice, she told Francis that a business should be “judged by how it treated the weak and the poor.”
Francis aimed to take this mantra to tourism. And show that responsible tourism can be commercially successful. Francis says: “I don’t see myself as a traditional business person. I’m an activist using business as a tool to change the world.”He overturned conventional thinking about travel businesses by creating a business model where travel companies and travellers could talk directly, booking declarations were made as part of an honesty-based system. Justin was one of the initial Trustees of British Charity The Travel Foundation, he sits on the Board of Basecamp Explorer Kenya. In 2016 The Times named Francis as one of the world’s 50 best ‘people to know in travel’. In 2018 he joined the UK Government’s Council for Sustainable Business, which advises The Department for Environment and Rural Affairs on how businesses can help deliver the aims of the 25 Year Environment Plan. Described by Lucy Siegle, eco writer at The Guardian as ‘the great activist traveller’ Francis’ mission is for a more caring travel and tourism industry.
He has described the tourism industry as the “biggest freeloader in the business world”saying, in an interview with The Guardian, that “broadly speaking, tourism globally has been unmanaged and never been taken by government. It’s fun, everybody’s happy, right? But tourism is one of the biggest and in some cases most aggressive industries on earth and it is taking governments a long time to recognise that it needs managing.”He has campaigned around the issue of overtourism – presenting a documentary on the issues, released in July 2018, the use of captive cetaceans in tourism, the ethics of voluntourism and many other issues associated with responsible tourism, including conservation and human rights. He has been outspoken about the ineffective use of carbon offsetting schemes. In 2004 he founded The Responsible Tourism Awards which responsibletravel.com ran until 2017. In November 2016, kidney failure and an inability to travel far as a result, gave Francis the inspiration to start the ‘Trip for a Trip’ scheme which would fund day trips for disadvantaged children around the world who lack the opportunity to travel
Hafeez-ur-Rehman Khan Dreshak is a Pakistani politician, a member of the National Assembly of Pakistan, from June 2013 to May 2018. He was born on 1 January 1957, he ran for the seat of Provincial Assembly of Punjab as a candidate of Pakistan Peoples Party from Constituency PP-248 in 2008 Pakistani general election but was unsuccessful. He received 15,452 votes and lost the seat to an independent candidate, Sardar Athar Hassan Khan Gorchani, he was elected to the National Assembly of Pakistan as a candidate of Pakistan Muslim League from Constituency NA-175 in 2013 Pakistani general election. He received 110,573 votes and defeated an independent candidate, Mir Dost Muhammad Khan Mazari
Adrian Marcu is a former professional tennis player from Romania. Marcu, a right-handed player from Hunedoara, began touring professionally in the early 1980s. Competing on the Grand Prix circuit, he was a doubles quarter-finalist at Viña del Mar in 1982 and made his only singles main draw appearance at the 1987 Mercedes Cup held in Stuttgart. In 1988 he won a Challenger title in doubles at Sofia; as a Romanian representative he won a bronze medal in doubles at the 1983 Summer Universiade and appeared in a total of 12 Davis Cup ties for his country, including a World Group relegation play-off against West Germany in 1984. He is a former coach of Simona Halep. List of Romania Davis Cup team representatives Adrian Marcu at the Association of Tennis Professionals Adrian Marcu at the Davis Cup Adrian Marcu at the International Tennis Federation
Reactions to the 2006 Lebanon War coming from the European countries. Ursula Plassnik, Austrian foreign minister, called for an immediate end to hostilities in Lebanon. "The blind force must stop," Plassnik said. "I appeal to the Israeli army and Hezbollah to stop their attacks and no longer oppose diplomatic efforts" to end the conflict, she said. Minister of foreign affairs Karel De Gucht and Prime Minister Guy Verhofstadt said that Israel has the right to defend itself, but has now responded with excessive violence. Verhofstadt called for the release of the captured Israeli soldiers; the Belgian-Lebanese leader of the Arab European League, Dyab Abou Jahjah, expressed his will to go to Lebanon to fight against Israel. Former High Representative Paddy Ashdown said that "It is not Hezbullah's position, weakening now, it is Israel's. Its stated war aim was to destroy Hezbullah, it is not clear why, having failed to do this by occupying Lebanon, it thought it could achieve it by bombing," he warned.
Bulgaria voiced its concern over the growing tension in the Near East region, Ministry of Foreign Affairs Spokesman Dimitar Tsanchev said in a press-release: "We condemn the kidnap of the two Israeli soldiers. We consider that the Shiite Lebanese organization Hisbullah should release them and cease the shooting against Israeli territory". "We bitterly condemn the bombing of the Israeli Army on Lebanon, which result in the death of tens of innocent Lebanese citizens. Israel should refrain from such actions and from breaking the borders of Lebanon," the release further said; the Danish foreign minister Per Stig Møller said that the Lebanese government has to take responsibility to prevent further terror attacks from Hezbollah in southern Lebanon. Israel has the right to act in self-defense, but is obligated to not use too strong measures. Finland, which holds the European Union's rotating presidency, has issued the following statement: "The European Union is concerned about the disproportionate use of force by Israel in Lebanon in response to attacks by Hezbollah on Israel.
The presidency deplores the destruction of civilian infrastructure. The imposition of an air and sea blockade on Lebanon cannot be justified."Finnish foreign minister Erkki Tuomioja, representing the EU in Israel, criticised Israeli "precision attacks" for hitting "everyone except Hezbollah" after the killing of four UN peacekeepers in southern Lebanon. "Israel could be destroying Lebanon while leaving the guerrilla group Hizbullah intact", stated Tuomioja on 11 August Foreign minister Philippe Douste-Blazy said the Israeli offensive on Lebanon is a "disproportionate act of war with negative consequences" which could "plunge Lebanon back into the worst years of the war with the flight of thousands of Lebanese who... were in the process of rebuilding their country.” Douste-Blazy condemned Hezbollah rocket attacks and the kidnappings of Israeli soldiers, asked for their immediate and unconditional release, called I call on all parties to "show restraint and not engage in a cycle of violence in which civilian populations would be the first victims".
French President Jacques Chirac castigated the Israeli offensive into Lebanon on 14 July. However, Israeli Army Radio reported that Chirac had secretly told Israeli Prime Minister Ehud Olmert that France would support an Israeli invasion of Syria and the overthrow of the government of President Bashar al-Assad, promising to veto any moves against Israel in the United Nations or European Union. Chancellor Angela Merkel says "We call on the powers in the region to seek to bring about a de-escalation of the situation. We can not confuse effect; the starting point is the capture of the Israeli soldiers. It is important that the government in Lebanon, on a peaceful path, should be strengthened, but it must be made clear that the capture cannot be tolerated; the attacks did not start from the Israeli side, but from Hezbollah's side." Sunday, German Development Minister Heidemarie Wieczorek-Zeul voiced criticism against Israel's attacks on civilian infrastructure in Lebanon, calling it "completely unacceptable."
Spokesman Evangelos Antonaros urged Hezbollah to release the captured Israeli soldiers. "Greece expresses its serious concern and is intensely troubled," the spokesman said. "It is vital, to stop the worsening, Hezbollah must release the soldiers taken hostage. At the same time, Greece calls on the government of Israel to avoid the use of excessive and pointless force which cannot provide a solution to the problem."A demonstration took place on 25 July, near the embassy of the United States, with slogans such as "Down USA, down Israel". The Italian foreign minister Massimo D'Alema said "We have the impression that the reaction is out of proportion and dangerous for the consequences it could have, I think that this, apart from some nuances, is the way the whole international community sees the situation." He added, "We are working for moves by the EU and the G8 in the next few hours to stop the spiral of violence," making reference to the G8 meeting planned for the weekend in St. Petersburg.
He condemned Hezbollah's assault on Israeli soldiers as "unacceptable," adding that Rome had asked for the release of the soldiers being held hostage. On 16 July there were reports that Italy was attempting to broker an agreement between Israel and Lebanon; the Israelis would agree to a cease-fire on two conditions: The return of the two soldiers captured on 12 July. The Army/Government of Lebanon would have to ensure that Hezbollah would pull back to the Litani River. Minister for Foreign Affairs Dermot Ahern said "It is now in the interests of everyone in the regi