Atomic Number: 90
Atomic Symbol: Th
Atomic Weight: 232
Melting Point: 3,182 F (1,750 C)
Boiling Point: 8,650 F (4,788 C)

Word origin: Thorium is named for Thor, the Norse god of thunder.

Discovery: Thorium was discovered as an element in 1928 by Swedish chemist Jons Jakob Berzelius. Berzelius received a sample of an unidentified black mineral from mineralogist Jens Esmark, whose son Morten Esmark had found it on Lovoya Island, Norway. Esmark suspected it contained an unknown substance. His mineral is now known as thorite.

Properties of thorium

Thorium is radioactive and decays at a fixed rate into a series of other elements. In its pure state, thorium is a silvery-white metal that is stable in air and retains its luster for several months. If contaminated with oxide, however, it tarnishes slowly in air. It turns gray and eventually black. [See Periodic Table of the Elements]

Thorium’s physical properties are strongly influenced by how much it is contaminated with oxide. Even the purest specimens of thorium often contain several tenths of a percent of oxide. Thorium oxide has a melting point of 3,300 C (5,972 F), the highest of all the oxides.

Pure thorium is soft, very ductile, and can be swaged, drawn and cold-rolled. When heated in air, its turnings ignite and burn with a brilliantly white light. Powdered thorium is pyrophoric, requiring careful handling.

Thorium is dimorphic, changing from a cubic to a body-centered cubic structure at 1,400 C (2,552 F). Thorium does not dissolve easily in most common acids (with the exception of hydrochloric) but water slowly attacks it.

Much of the earth’s internally produced heat is attributed to thorium and uranium.

Sources of thorium

As a primordial nuclide, ²³²Th has existed in its current form for more than 4.5 billion years. Its existence predates the formation of Earth. Thorium was formed in the cores of dying stars through the r-process, and supernovas eventually scattered it across the galaxy. Its half-life is comparable to the age of the universe.

Small amounts of thorium are found in most rocks and soils. Soil usually has an about 6 parts per million of thorium. Thorium is found in several minerals, including thorianite, monazite, and thorite. They occur on all continents, and thorium is now considered three times more abundant than uranium, or about as common as lead and molybdenum.

Thorium is recovered commercially from rare-earth minerals and monazite, which is anything from 3-to-9 percent thorium. High-purity thorium has been made, and there are several methods for producing thorium metal.

Uses of thorium

Historically, thorium’s primary use was for the Welsbach mantle used in portable gaslights. Along with other ingredients, the thorium in these mantles produced a dazzling light when heated with a gas flame.

Today, thorium metal is used as a source for nuclear power. Thorium-cycle converter-reactor systems are in development. Thorium’s abundance means that there is probably more energy available from thorium than from both uranium and fossil fuels, but any significant demand for thorium as a nuclear fuel is still several years in the future.

Thorium is also used to coat the tungsten wire found in electronic equipment. Its presence as an alloying element in magnesium, imparting high strength and slowing resistance at elevated temperatures, plus its low-work function and high electron emission make it an excellent source for coating tungsten wire. Thorium oxide is also used to control grain size in tungsten when used in electric lamps and in high-temperature laboratory crucibles. Additionally, thorium oxide is useful as a catalyst in ammonia-to-nitric acid conversion, in petroleum cracking, and in sulfuric acid production.

Gases containing thorium oxide are useful in producing high-quality camera lenses and scientific instruments. These gases have a high refractive index and low dispersion. ²³²Th is radioactive enough to expose a photographic plate in a few hours.

Isotopes of thorium

Thorium has 27 known radioisotopes. They range in atomic weight from 210 to 236 and all are unstable. ²³²Th is by far the most stable with a half-life as long as the universe — 14.05 billion years. Other isotopes are short lived, and are actually intermediates in the decay chain of higher elements. Only trace amounts of them are found. The longer-lived of these trace isotopes include: ²³⁰Th with a half-life of 75,380 years which is a daughter product of ²³⁸U decay; ²²⁹Th with a half-life of 7,340 years and ²²⁸Th with a half-life of 1.92 years. All of the remaining radioactive isotopes have half-lives that are less than 30 days and the majority of these have half-lives less than 10 minutes.

²³²Th contains almost all naturally occurring thorium. It is an alpha emitter and goes through six alpha and four beta decay steps before becoming the stable isotope ²⁰⁸Pb.

Coal is no cure for energy poverty

Posted Fri 11 Apr 2014, 2:20pm AEST

Photo: Decentralised renewable energy is safer and cleaner than coal-fired power generation. (Reuters: David Gray)

Coal is mired in deep social inequities, and the need of the hour is a decentralised, democratically-owned renewable energy deployment to fight energy poverty, writes Chaitanya Kumar.

Coal does not alleviate poverty, it aggravates it. We of course rarely ask the poor what poverty means to them and what it will take to move them out of it. But Brendon Pearson, the chief executive of the Minerals Council of Australia, says we need coal-fired power to pull the world’s poor out of energy poverty.

But to be fair on Mr Pearson, you could arrive at that conclusion too if you deliberately ignored the social and economic contexts of coal in India or the developing world at large.

A recent study has shown that coal pollution in India results in 80,000 to 115,000 premature deaths every year and this statistic is expected to rise to 1.5 million if we continue on our current path.

Coal remains the single biggest contributor to climate change, the devastating impacts of which are already being suffered by the poor and most vulnerable. In fact, the International Energy Agency itself has called for a massive overhaul of existing fossil fuel plants and mines, suggesting that if we are to contain global warming to a two-degree rise, no new energy intensive infrastructure can go online post 2017.

Coal is mired in deep social inequities. Travel to any major coal belt in India and the people living around a coal plant face regular power outages. This cruel irony is explained by the fact that the power generated is often for the cities, the energy guzzlers, while the negative residual impacts of coal are to be borne by those living next to it. The industry is often set up on the pretext of providing jobs, greater compensation for land and adequate rehabilitation and resettlement for displaced communities. None of these promises have ever been satisfied and the coal belts of India stand testimony to that fact.

Coal and corruption are synonymous. Take the recent case of the National Thermal Power Corporation (NTPC) of India, the largest coal power generator of the country. It received clearance from the federal environment ministry to set up a 2400 MW coal plant in southern India. The clearance was recently revoked when it was found, through images from Google Earth submitted by a local petitioner, that the proposed site was prime agricultural land as opposed to a barren land that the company had claimed it to be. Such is the haste of the Government to approve projects that not a single visit to the site was undertaken to verify the company’s claims. If you believe such corruption could never happen in Australia, look to the recent ICAC findings concerning Eddie Obeid.

Decentralised renewable energy is a safer, cleaner and viable source of energy for the rapidly evolving societies of the coming decades.

Various grassroots groups that have taken shape over the last decade are struggling to curtail the coal industry’s expansion. Millions of people now recognise the myth that coal equals development and are putting up a tough front against it. Why would they do so when, according to Mr Pearson, they need it for becoming poverty-free?

The answer of course lies in the simple adage that you can’t solve a problem with the same thinking that created it. With 40 per cent transmission and distribution losses across the grid, a heavily nationalised process of mining and generating power and the recent rise in consumer tariffs, coal is not the solution but in fact the reason that 300 million-odd Indians continue to live in darkness.

The need of the hour therefore is a decentralised, democratically-owned renewable energy deployment to fight energy poverty. Glimpses of its success and reliability are already being felt across the world. Decentralised renewable energy is a safer, cleaner and viable source of energy for the rapidly evolving societies of the coming decades.

The banks and financial institutions are increasingly wary of investing in coal and rightly so. The fossil fuel divestment movement in Australia, North America and Europe coupled with local community struggles are a force to reckon with. It is no longer a debate that only the so-called environmentalists are engaging in with the coal industry but everyone from boardrooms to the common people are in it too.

Pearson and his colleagues are clearly making a last ditch effort to revive an obsolete and dangerous industry and we would do our future generations and ourselves a favour by giving coal the boot.

This article was first published at ABC Environment. Read the original here.

Chaitanya Kumar works as the South Asia campaigns coordinator for 350.org. He is based in New Delhi and works on issues of coal and climate change. View his full profile here.

Why this ad? CEC Callaghan Electrical – www.cecontractors.com.au – Our Focus is Safety & Excellence Domestic, Comercial & Industrial

Geology News fb@geology.com via google.com	11:59 PM (8 hours ago)
to me

Geology.com News – 11 Topics

• Monitoring Sacramento River Levees with Radar?
• Rare Earths in Seafloor Nodules Off Bermuda?
• Military Armor Inspired by Twinning in Mollusk Shells?
• Burning Marcellus Gas in Ontario
• New USGS Topo Maps of Utah
• The Contraction of Mercury
• Will Yellowstone Erupt in Our Lifetime?
• What is Causing the Oklahoma Earthquakes?
• South Dakota Sand and Fracking Specs
• Satellite Data and Corn Belt Productivity
• Mineral Hardness Picks

Monitoring Sacramento River Levees with Radar? Posted: 10 Apr 2014 05:25 AM PDT “In the Sacramento River delta north of San Francisco Bay, islands, agricultural lands and communities below sea level are protected from surrounding water channels by more than 1,100 miles of dirt levees, many of which date back to the California Gold Rush.” NASA now has a method to monitor them using radar. Quote from the NASA press release.

Rare Earths in Seafloor Nodules Off Bermuda? Posted: 10 Apr 2014 05:17 AM PDT Some mineral experts say that Bermuda’s Exclusive Economic Zone has a rich resource of polymetallic nodules that are rich in rare earth elements. Related: What are Rare Earth Elements?

Military Armor Inspired by Twinning in Mollusk Shells? Posted: 10 Apr 2014 05:17 AM PDT “The shells of a sea creature, the mollusk Placuna placenta, are not only exceptionally tough, but also clear enough to read through. Now, researchers at MIT have analyzed these shells to determine exactly why they are so resistant to penetration and damage — even though they are 99 percent calcite, a weak, brittle mineral.”

Burning Marcellus Gas in Ontario Posted: 10 Apr 2014 05:17 AM PDT About 30 percent of the natural gas used in the Province of Ontario, Canada is produced from the Marcellus Shale.

New USGS Topo Maps of Utah Posted: 10 Apr 2014 05:13 AM PDT USGS announced that they have published new topographic maps and orthophoto images for the state of Utah in pdf format. A small sample of the Moab quad is shown below. If you want to see it full size in a pdf document click here (28 megabytes).

The Contraction of Mercury Posted: 10 Apr 2014 05:03 AM PDT “Unlike Earth, with its numerous tectonic plates, Mercury has a single rigid, top rocky layer. […] New global imaging and topographic data from MESSENGER show that the innermost planet has contracted far more than previous estimates.” Quoted from the Carnegie Institution for Science press release.

Will Yellowstone Erupt in Our Lifetime? Posted: 10 Apr 2014 04:59 AM PDT “Yellowstone is like a conveyer belt of caldera clusters,” he says. “By investigating the patterns of behavior in two previously completed caldera cycles, we can suggest that the current activity of Yellowstone is on the dying cycle.” Related: The Volcano Beneath Yellowstone

What is Causing the Oklahoma Earthquakes? Posted: 10 Apr 2014 04:54 AM PDT During 2013 the state of Oklahoma experienced 109 earthquakes with a magnitude of 3 or higher. Already this year the state has equaled that number. Some people blame wastewater injection. The Wichita Eagle reports that Kansas is also experiencing a number of earthquakes.

South Dakota Sand and Fracking Specs Posted: 10 Apr 2014 04:52 AM PDT The South Dakota Department of Environmental and Natural Resources conducted a study on 256 sand samples collected from the western part of the state to determine if they could be developed as frac sand sources for use in wells that use hydraulic fracturing in North Dakota’s Bakken formation. Related: What is Frac Sand?

Satellite Data and Corn Belt Productivity Posted: 10 Apr 2014 04:35 AM PDT “Data from satellite sensors show that during the Northern Hemisphere’s growing season, the Midwest region of the United States boasts more photosynthetic activity than any other spot on Earth, according to NASA and university scientists.” Quoted from the NASA press release.

Mineral Hardness Picks Posted: 10 Apr 2014 04:25 AM PDT Mineral hardness picks are pencil-like tools that have points made from materials that match the hardness of minerals in the Mohs Hardness Scale. With them you can easily test the hardness of mineral grains in a rock and test the hardness of small-size specimens. In our opinion they are easier to use than pieces of minerals and allow you to obtain more accurate results. They also do not contaminate your specimen with particles of the hardness mineral.

Sydney’s iconic “red rattler” trains were finally pensioned off more than 20 years ago, and ever since the city’s passenger railway network has been dominated by double-decker carriages.

But NSW Premier Barry O’Farrell says that was the wrong call by transport planners.

“Single-deckers… can carry more people, travel more quickly, and disembark those people more quickly without people having to come down from those difficult steps that exist on our double deckers and that delay people at railway stations,” Mr O’Farrell said.

Single-deck trains will be returning to the Sydney rail network in the next five years with the North West Rail Link. That $8.3 billion project has created controversy because double-deck carriages will not be able to run on the new line.

ABC Fact Check asked Mr O’Farrell’s office if he meant to imply individual single-deck trains can carry more passengers than a double. A spokesman said he did not; rather that single-deckers can carry more passengers per hour overall.

The North West Rail Link

Due for completion by the end of 2019, the new line between Chatswood on Sydney’s north shore and Rouse Hill in the north-west will require 15 km twin tunnels to be dug.

The project’s website says those tunnels will be six metres in diameter, large enough to carry the new generation of single-deck trains, but not the existing Sydney double-deckers.

A June 2012 project overview said: “Single-deck trains have the advantage of being able to load and unload quickly at stations, allowing more trains per hour on any given line.”

The tunnelling and station excavation contract is worth $1.15 billion, according to a report from the NSW Government agency Transport for NSW. Enlarging tunnels and stations for double-deckers would cost $200 million more than for singles. The same document says a double carriage costs $1 million more than a single one.

The project’s website says the new single-deckers will be driverless and automated “metro” style trains, with sliding screen doors on platforms for safety.

The NSW Government identified some of the features of the trains in its report Sydney’s Rail Future,including:

• Three or more doors per side per carriage (compared to two doors on exisiting double-deckers)
• Level access between platform and train
• A mixture of seating areas

The configuration of the carriages will be finalised following procurement, however the project overview calls for single-deck trains capable of moving up to 1,300 people.

At peak times, the website says, trains will run at least every five minutes – a rate of 12 services per hour. A Transport for NSW spokesman says the new line will have the capacity to increase to up to 20 trains an hour as demand grows. On that basis, the new line could move between 15,600 and 26,000 passengers per hour.

The full journey from Cudgegong Rd at Rouse Hill to Chatswood is expected to take 37 minutes. Passengers will then be required to change trains at Chatswood from the single-deckers to double-deckers to continue their journey into the city and beyond.

Sydney’s double-deckers

Double-deck trains began appearing on the Sydney suburban passenger rail network 50 years ago to increase capacity without the need for major engineering works.

Although described as double, they have always been a hybrid with a single deck at each end near the doors, and a double “gondola” in the middle between the bogies. The 1964-vintage Tulloch double deckers effectively doubled the capacity of each train.

The Tulloch carriages had seating for 132 passengers and standing room for 146 more, compared to 70 seats and around 60 standing on the earlier single-deck C-class red rattlers also known colloquially as “Sputniks”. The last of the old-style single-deck trains were retired in the early 1990s.

The double-deckers on the Sydney rail network now carry about a million passengers each weekday. They frequently run at a rate of up to 15 services per hour.

Comparing capacity

The newest trains running in Sydney are the double-decked Waratahs, whose eight-car trains have a seating capacity of around 900 and according to Sydney Trains a total “reliable capacity” of 1,210 seated and standing.

But it is possible to pack many more people into a Sydney train than that. Tests by RailCorp in 2007 found the maximum practical load of an eight-car double-deck train is 1,750, but only if it is a single destination special such as for a major sporting ground where all passengers get on and off at once.

Double-decked trains overseas such as the MI09, which entered service with the Paris RER Line A in 2012, can carry up to 1,725 passengers in just five carriages. This translates to a notional eight-car capacity of 2,760.

The capacity of single-deckers has increased since the days of the red rattlers, with many now favouring seats along the walls and increased standing room in the middle rather than rows of seats across the carriage.

A look at interstate and international trains suggests the North West Rail Link target capacity of 1,300 per single deck train is realistic if a high proportion of passengers stand. Queensland Rail’s SMU and EMU fleet are single deck, and carry up to 500 passengers in a three-carriage train (240 seated and 260 standing), giving a notional eight-car capacity of around 1,330.

Hong Kong’s Mass Transit Railway boasts a total capacity of 2,500 passengers on its single-deck eight-car trains on the Tsuen Wan Line, with no separate data available on the number of those who can be seated.

Estimates contained in a report by Infrastructure NSW state double-deck and “single-deck comfortable” trains both have a total capacity of 1,200, with 890 seats on the double-decker and 600 on the single.

Given the almost unlimited variations between carriage size and design, a direct capacity comparison between doubles and singles is problematic.

However, transport economist Neil Douglas, who has conducted extensive research for the NSW Government, puts the practical capacity at 1,400 for doubles and 1,120 for singles.

Train dwell times

Mr O’Farrell says people can disembark more quickly from single-deck trains than doubles.

A range of factors can extend “dwell time”, the time a train must wait at a platform for passengers to get off and on. These include the number of doors and stairs on the train and crowding levels in the carriage or on the platform.

According to data compiled for the NSW Government by the engineering firm Parsons Brinckerhoff, double-decker dwell times at Sydney stations range from 35 seconds at suburban stations to 70 seconds in the central business district. By way of comparison the single-deck Dubai Metro, which claims to be the world’s longest automated train service, keeps boarding times at stations down to an average of just 30 seconds.

Parsons Brinckerhoff modelling, quoted in a report from Dr Douglas’s Douglas Economics, assumes single-deck trains have a dwell time 10 seconds less than double-deckers at the busiest stations in Sydney.

Using the Douglas Economics capacity estimates, the North West Rail Link would carry between 13,440 passengers on the 12 trains per hour specified by the project overview, and an eventual 22,400 on the 20 services predicted by Transport for NSW.

Twelve double-decker trains per hour would move 16,800 passengers and 20 trains would move 28,000.

That gives doubles a 5,600 passenger per hour advantage at 20 trains an hour, which is equal to another five single-decker trains carrying 1,120 passengers per hour.

However, according to his research, Dr Douglas says it would only be possible to run an additional two single deck trains per hour, resulting in a peak load of 25,000 passengers per hour.

The impact of new technology

The Infrastructure NSW report says the new “metro” style of driverless single-deck train has a maximum load of 2,000 passengers with 400 seated and 1,600 standing.

The report states conventional single-deck and automated single-deck “metro” trains are both capable of running 30 services per hour, while it says double-deckers can only run 20.

However that difference of 50 per cent cannot be explained by a relatively short dwell time difference of around 10 seconds per stop.

The report says those assumptions also depend on “the introduction of new train control systems, using technology that is proven in service overseas”.

Dr Douglas says the 20-per hour limit on double deckers is due to signalling, which only allows for a maximum of one train every three minutes, and equally applies to single-deckers.

Improvements to signalling would allow 24 double-deck trains per hour carrying a peak load of 33,000 passengers per hour. Alternately, it would also allow for 26 single deck services an hour, with a peak load of 29,200 passengers.

Equally, other improvements foreseen in the new “metro” single deckers can also apply to double-deckers.

Dr John Stone, who lectures in urban planning at the University of Melbourne, says double-deckers could be made faster. “Double-deckers don’t need to cause long dwell times,” he said. “Platform signs that show where doors will be and the overall sense of the importance of speed allow double-deckers to work well in Europe.”

Double-deckers such as the Paris MI09 have added a third pair of doors in each carriage to speed up the boarding process and reduce dwell times.

In theory, according to Dr Douglas, double-deckers could also be automated and achieve comparable time savings. “I can see no reason why future double-deckers could not operate in exactly the same way as a single-decker – driverless or not,” he said.

Experts weigh the merits

Professor Graham Currie from the Institute of Transport Studies at Melbourne’s Monash University says that the shorter dwell time of single-deckers only partly counteracts the benefit of the larger capacity double-deck cars.

Dr Phillip Laird, a rail transport expert at the University of Wollongong, says double-deckers are better for long distances, while single-deckers are better for short trips in the CBD and to the airport.

And Dr Stone agrees it isn’t an either-or proposition. “The Sydney rail system has need for both for different trip types,” he said.

However, Dr Douglas cautions passengers simply won’t want to spend a 37 minute journey standing up and that a lack of seats will lead to lower passenger demand on the North West Rail Link.

Dr Laird also says the new line would be better served by double-deckers given the distance from the city.

The verdict

Given their smaller passenger capacity, single-deck trains can only transport more passengers than doubles by running significantly more services per hour. However, the dwell time saving of single-deck trains is relatively slight, by one estimate only allowing for two additional services per hour.

Any other time savings are derived from automation or improved signalling, which can be applied equally to singles or doubles.

Unlike the red rattlers, newer singles often boost their capacity by having most passengers travel standing. While this raises concerns about passenger comfort on longer trips, the same decision to reduce the number of seats could also apply to double-deckers, which would still have greater capacity.

Mr O’Farrell’s claim is doubtful.

Sources

• Barry O’Farrell, press conference, March 24, 2014
• Transport for NSW, ‘$8.3 billion North West Rail Link to open in late 2019’, June 16, 2013
• Transport for NSW, North West Rail Link website
• Sydney Trains, Waratah
• Sydney Trains, Facts and stats
• NSW Government, Sydney’s Rail Future, June 2012
• NSW Government Environment and Heritage, T 4801, Tulloch Suburban Trailer Car
• Infrastructure NSW, State Infrastructure Strategy, Passenger trains
• Dubai Metro, Metro Express
• Douglas Economics, Modelling Train & Passenger Capacity, July 2012
• Queensland Rail, Suburban Multiple Unit (SMU200)
• MTR Hong Kong
• Alstom, ‘MI09 makes first journey on Paris’ RER A line’, January 30, 2012