A new graphene-based transistor in which electrons travel both over a barrier and under it (by tunneling) has exhibited one of the highest performances of graphene-based transistors to date.
 
The combination of the two types of transport enables the transistor to achieve a large difference between its on and off states, giving it a high on/off ratio, which has so far been difficult to achieve in graphene-based transistors. With this advantage, in addition to its ability to operate on transparent and flexible substrates, the new transistor could play a role in post-CMOS devices that are expected to be able to compute at much faster speeds than today's devices.

The researchers from the University of Manchester in the UK, who designed the new graphene-based transistor, have published their study on the device in a recent issue of Nature Nanotechnology.

As the researchers explain in their study, other graphene-based transistors have previously been demonstrated, many of which have a sandwich structure with atom-thick sheets of graphene forming the outer layers and a different ultrathin material forming the middle layer. This middle layer can consist of many possible materials. In the current study, the researchers used two-dimensional tungsten disulphide (WS2) as the middle layer, which served as an atomically thin barrier between the two layers of graphene.

The biggest advantage of using WS2 compared to most other barrier materials is that WS2's chemical properties allow electrons to cross either by going over the barrier, as in thermionic transport, or under it, as in tunneling. In the off state, very few electrons can cross the barrier by either transport method, but they can cross by one or both methods in the on state.

Switching between the two states involves changing the transistor's gate voltage. A negative gate voltage creates the off state, since it increases the tunneling barrier height so that few electrons can cross the barrier. A positive gate voltage switches the transistor to the on state by reducing the tunneling barrier height and—if the temperature is high enough—allowing over-barrier thermionic current as well.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Prices, WML Version: http://m.chinatungsten.com

What topics should CFOs get their arms around so they won't seem out of touch at board meetings this year?

As a CFO, you’re probably not a member of the company’s board. But you might as well be. You attend the greater portion of most board meetings and are asked for a lot of input.

But are you always fully prepared? After all, a new hot item may pique the board’s interest at any time.

Conflict Minerals
It’s just one of the 398 rulemakings required by the Dodd-Frank Act (and one of 136 that have been finalized). But the Securities and Exchange Commission’s new regulations regarding “contract minerals” promise to be prominent in boardroom discussions this year and perhaps next.

The SEC estimates that about 6,000 U.S. companies, or 40% of the­ approximately 15,000 publicly held ones, will be subject to heavy new compliance requirements. That is, any company that sells products containing gold, tantalum, tin, or tungsten, or otherwise uses those substances in making products, must publicly report on the metals’ movement through its supply chain. The purpose is to determine whether they were mined in the Democratic Republic of Congo and surrounding countries, where warring parties have been looting mines for years and selling the four metals in the global market to fund their violent activities.

The reporting requirement begins in May 2014. But companies’ initial reports must cover calendar-year 2013 supply-chain activities. Reports containing false or misleading statements could expose CFOs to liability under securities laws.

Most public companies in the aerospace, automotive, construction, electronics, industrial equipment and tools, jewelry, and medical equipment industries will be subject to the rules. Privately held companies could be at risk as well, if they supply products to public companies. In the aggregate, companies will spend several billion dollars to comply with the regulations, says Dennis Whalen, executive director of KPMG’s Audit Committee Institute.

“It’s going to be an awful lot of work for companies,” says Richstone, noting that the matter did not get on many boards’ radar screens until fairly recently.

At a board meeting where she first heard about it, “we all sat there with our mouths hanging open, saying is this for real?”

Several lobbying initiatives funded by corporations are under way in Washington over the issue, most notably one spearheaded by the Direct Marketing Association, Friedman notes.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Prices, WML Version: http://m.chinatungsten.com

HOUSTON, TX -- 01/22/13 -- Vantage Drilling Company ("Vantage")  announces today that it has received a conditional letter of award for its newbuild drillship the Tungsten Explorer to work in West Africa. The award is for a period of up to four years commencing in mid 2014.

The contract has a minimum duration of two years, while the customer has four six-month options to extend the contract. The letter of award is subject to customary conditions including negotiating the final terms of the contract which is anticipated to be completed in the first quarter 2013. The estimated revenue over the initial two year firm period of the contract is approximately $468 million, including mobilization.

W Resources expects the La Parrilla tailings project to be in production in the second half of 2013 - after it received final approval.

The regional authority of the Junta de Extremadura has given the go-ahead for the project in Spain, the firm told investors.

Annual plant feed is expected to be around 330,000 tonnes and annual production anticipated to be 28,000 MTU (metric ton unit) of tungsten and 26 tonnes of tin.

LAWRENCE, Mass — A benchtop reflectance probe for qualitative and quantitative mineral analysis in the core logging shack or the lab has been unveiled by Spectral Evolution. It provides geologists and field researchers with hands-free measurement across the spectral range from 350 to 2500 nm.

It delivers easy-to-use sample analysis for identifying iron oxide minerals, Al(OH) group minerals, MH4 minerals, Fe(OH) group minerals, Mg(OH) group, carbonate group, OH-bearing silicates, Zn silicates/phosphates, zeolites, rare-earth-element-bearing minerals and sulfides.

The probe features “no threading” setup with an external SMA-905 port and power connector, a 5-W tungsten halogen source with a user-replaceable probe, compatibility with all of the company’s spectrometers, and a sapphire window for durability.

It can be ordered separately or as part of a Spectral Evolution mining bundle.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Prices, WML Version: http://m.chinatungsten.com

Larson Jewelers an authorized dealer of the Triton Rings line, a division of Frederick Goldman, has just announced they now carry 4 mm and 5 mm wide Triton rings made of tungsten carbide. 4 mm and 5 mm wide tungsten rings are ideal for women or men who prefer narrow bands.

The debut of this long anticipated narrower tungsten wedding bands line is happening just in time for the Valentine’s Day shopping season. For years Triton has focused only on 6 mm to 9 mm wide rings, which are the widths men traditionally wear. Now, couples who wish to have matching Triton branded wedding bands can finally do so, and Larson Jewelers is one of the few jewelers who have full authorization to carry this reputable jewelry line.

Triton is starting off with 6 great styles; 3 styles in 4 mm and 3 styles in 5 mm. Styles range from classic plain polished domed rings to beautifully carved designs. “When we first started carrying the Triton line last year, we asked if they will have a 4 mm or 5 mm line for women and they said they would, but we didn’t think they would come out with it this fast.” says Thomas Larson, co-founder of Larson Jewelers.

As mentioned, this line is not specifically geared towards women. Many men who are not used to wearing rings will also prefer to have a narrower band because it will not feel as bulky. Make no mistake these rings are narrower, but they are by no means weaker. Triton’s renowned toughness is engineered into this line as well. As with all tungsten ring brands Larson Jewelers carry, Triton Rings, come with a manufacturer’s lifetime warranty, which covers size exchanges for life, and repair or replacement in case of accidental damage. It is part of their policy to only carry brands from manufacturers that stand behind their products.

Tungsten Jewellery Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-jewellery.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Prices, WML Version: http://m.chinatungsten.com

New U.S. reporting requirements on sourcing “conflict minerals” create challenges and opportunities for companies.

You paid $100 for an organic heirloom turkey for your holiday table. Your fair trade coffee costs $16 per pound. And the hand-crocheted organic cotton blanket from a Peruvian co-op for your new baby niece? As much as $220 plus shipping.

Sustainable merchants have established strong niche markets for luxuries and incidentals. But what about an essential tool like your smart phone? Would you pay more if you could be sure its materials weren’t indirectly bankrolling human rights abuses in a distant frontier like the Democratic Republic of Congo?

New Reporting Requirements For Conflict Minerals

Creating a new economic framework amid anarchy is just one dilemma facing companies in the U.S. subject to new reporting requirements for “conflict minerals” by the Securities and Exchange Commission. These minerals are crucial to electronics and widely used in many products.

Other challenges: understanding and complying with the new federal reporting requirements, untangling complex global supply chains and quelling fears of both suppliers and customers.

As the DRC government and rebels consider a new round of ceasefire talks, companies are now determining whether to keep sourcing materials from the DRC under the new regulations, or source from other nations.

“It would be easier to just stay out of it,” said Michael Loch, director of supply-chain corporate responsibility for Schaumburg, IL.-based Motorola Solutions.

“But from a CSR standpoint, you don’t want to make a bad situation worse, “Loch said. “If there is enough momentum and people stay engaged, you can see how a legitimate pipeline can be established and eventually we will see this as a normal way of business.”

Companies See Compliance Challenges 

Other companies say the conflict minerals regulations penalize them for circumstances far beyond conflict mineralstheir influence. More than a year before the first conflict minerals report is due to the SEC in 2014, they are feeling the pinch from customers asking them to certify that their products are conflict-free.  Yet, they can’t see clearly down their supply chains back to the materials’ origins – often small “artisan” mines under the control of warlords.

“We do not want to purchase any components where the manufacturer purchases raw materials from the DRC region, “ said Michael Goeringer, president of Arc-Tronics, an Illinois-based circuit board manufacturer. “However, we have no mechanism to determine if they are doing that or not.”

Four materials – tin, tantalum, tungsten and gold – are covered by the new regulation, which was required in the 2010 Dodd-Frank Act. A percentage of the world’s supply comes from mines on the eastern frontier of the DRC, where millions have been killed or uprooted in a civil war that has persisted for more than a decade.

Next year, U.S. public companies will be required to report their use of “conflict minerals” exported from this tropical twilight zone in a new effort by policymakers to choke off the outlaws’ financing and establish a legitimate economy. They must report their audited findings to the SEC.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Prices, WML Version: http://m.chinatungsten.com

Australia - Strategic Elements has kicked off rock chip and pan concentrate sampling at the Mt Rangitoto prospect on the West Coast of the South Island, New Zealand.

The company is targeting intrusion related gold, silver and rare metals around the historic Mt Rangitoto gold-silver mine.

The focus on intrusions is due to the large-scale nature of this style of deposit.

Mt Rangitoto, which forms part of the West Coast " Hohonu Project, comprises a high grade historic gold-silver mine and streams draining the mountain that contain high grade tungsten, tin, tantalum and niobium.

High grade gold samples of 21 grams per tonne (g/t), 29g/t and 32g/t have been reported from the Mt Rangitoto Mine.

High grade silver samples of 43g/t, 79g/t, 110g/t and 1,400g/t have also been discovered.

In previous pan concentrate sampling of the streams draining the mountain, grades of 1% tin and 1% tungsten have been returned.

The Mt Rangitoto Mine is believed to host gold in granite, with samples of 0.62g/t gold and 0.55g/t gold returned from previous exploration.

There is strong potential for metal to be sourced from a buried intrusion. Potential buried granite may preserve rare and precious metals.

Veins and silver in the mine increased with depth towards a granite.

Strategic Elements controls a large strategic area of over 1,350 square kilometres of highly prospective ground on the South Island.

The Hohonu Project covers over 10 separate intrusions with several primary areas of rare metal "rare earths, tungsten and tin " mineralisation.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Prices, WML Version: http://m.chinatungsten.com

In this ‘insights from industry’ interview, Dr Yuri Zhuk, Technical Director at Hardide Coatings Ltd., talks to AZoM regarding the importance of seal reliability, especially in adverse conditions.

GT: Could you please provide a brief overview of Hardide and some of the new coatings that Hardide is producing?

YZ: Hardide Coatings Ltd, an advanced surface coating company, is a leading innovator in the development and production of metal surface coatings based on Tungsten Carbide. The company is currently producing the Hardide range of chemical vapour deposition (CVD) tungsten carbide / tungsten hard coatings, which have exciting and wide-ranging applications in industries including oil and gas, valves, pumps, aerospace and advanced engineering..

GT: What are the primary applications of these coatings?

YZ: Applications where wear, erosion, corrosion or chemically aggressive media cause component and tool or equipment downtime, failure or loss of performance. The coatings are hard, tough, flexible, ductile and impact resistant and can coat internal surfaces and complex geometries so can be used in many applications where traditional hard coatings are not suitable.

An important application of these CVD coatings is their use on mechanical seals for heavy-duty rotating equipment.

Rotating equipment, including turbines, compressors and pumps, use mechanical face seals to prevent leakage, whilst also excluding any abrasive media and lubricating the mechanical assemblies. The importance of seal reliability cannot be overstated when looking at overall equipment reliability, because seal failure results in the damage of costly equipment, and would also cause higher downtime costs.

GT: Which industries benefit from these coatings?

YZ: Primarily the oil, gas and chemical processing industries will benefit from Hardide’s CVD coatings for mechanical face seals. However, any industry that employs heavy-duty mechanical face seals will benefit, especially if these are employed in adverse conditions.. In particular, these coatings are used to make the ‘primary’ sealing surface durable and capable of resisting three-body abrasion, erosion and corrosion.

 GT: What materials are traditionally used on mechanical seals and what are the limitations of these?

YZ: Solid hard materials, such as ceramic, silicon carbide, or sintered tungsten carbide are frequently used. However, these materials have several significant limitations and disadvantages, which are listed below:

    They are brittle
    They are expensive and difficult to produce (especially if there are finer features included in the seal design)
    The thermal expansion properties of these materials can differ significantly from steel, leading to jamming with a change in temperature.

HVOF, plasma spray coatings (such as WC/Co), DLC and other PVD coatings are already used on mechanical seals. However, these are often not effective for heavy-duty seal applications. For example, WC/Co HVOF and plasma spray coatings contain hard WC grains in a soft cobalt binder. These coatings can become very rough in abrasive/corrosive environments due to the selective leaching or abrasion of the binder.

GT: How do the Hardide coatings address these common problems?

YZ: An even wear pattern is ensured by the uniform structure of Hardide coatings, so an optimum finish can last for longer without hard asperities forming. Both tungsten carbide and tungsten have excellent resistance to chemically aggressive/corrosive media, particularly acids. The coating might be further alloyed with small amounts of Fluorine or Fluorocarbons (as disclosed in Hardide patents), which can further enhance its mechanical properties.

An alternative approach is to manufacture the mechanical seal components out of steel and then coat with a hard coating. Using steel is beneficial for the following reasons:

    It is tough
    It is inexpensive
    It can lead to improved and larger ranges of seal design
    It is relatively easy to machine

GT: How does using CVD tungsten carbide coatings effect the lifespan of machinery?

YZ: It has been shown that the coatings can triple the operational life of critical parts in abrasive conditions. Mechanical face seals display similar, long-lasting results.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Prices, WML Version: http://m.chinatungsten.com

BERLIN - Whether it is its solidly high price per ounce or maybe even the end-of-year visit of Her Majesty, Elizabeth II, to view British gold reserves at the Bank of England, conspiracy theories are proliferating around gold – particularly as (or so rumor has it) some kilo bars appeared in Great Britain that were filled with virtually valueless wolfram.

Some insiders even believe that a large portion of Germany’s gold reserves are in fact gold-coated wolfram (tungsten) bars. The sheer values involved – a standard 12.44 kg gold bar is presently worth 500,000 euros – go a long way to explaining the stubborn attachment to theories such as these, the spread of which are aided considerably by the Internet, reports Die Welt.

The precious metal had another strong week, with gold's spot price closing Friday at $1,687 per ounce.

Eugen Weinberg, who heads commodities research at Germany’s Commerzbank, says that he is certain that – if indeed there are any tungsten-filled bars at all out there – the number of them is exceedingly small.

German theorists’ fears are particularly fueled by the fact that, according to the German Federal Bank itself, only part of German gold reserves are actually in Germany: the bank says that “a good two thirds” of the 3,396 ton German reserves worth 145 billion euros are not actually stocked inside the country.

Among the rumors accompanying the nearly two-year upward trend in gold prices is that key national treasuries – not least Fort Knox in the United States – have now actually been emptied out. Another fashionable conspiracy theory sees price manipulation of the precious metal by a powerful international elite that controls the market.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Prices, WML Version: http://m.chinatungsten.com